Among all the sacred mantras India has seen since times immemorial, Gayatri is held in the highest esteem and all our sacred texts and books hold a unanimous view that for Brahmins no other mantra is greater than Gayatri.

What is a Mantra ?
A mantra is a very very brief prayer or a salutation to a deity that is supposed to grace the devotee if chanted for a fixed number of times regularly. In general all the mantras require to be chanted 108 times but Gayatri can be chanted even 10 times. A mantra is packed with supernatural powers with a lot of hidden meaning though outwardly it may look very simple. Therefore both the giver of a mantra (the instructor or the guru) and the receiver (the shishya) should first deserve and understand their respective positions. Otherwise a mantra will become impotent bringing no results at all.

Gayatri Mantra :
Although all the mantras in Rigveda are the holy words of which none can be considered high or low in respect of power and potence, the Gayatri has a special place in the Vedic literature. We come across this mantra in the Third Mandala as the tenth mantra in the 62nd Sukta. The sage is Vishwamitra and the metre is Gayatri and the deity of the mantra is the most gracious one - Savita, the sun-god or the presiding deity of the sun. Because of 'sandhi' or the combination of words in the mantra the name of the deity Savita, is hidden and many of us will be surprised to-day if we state that the deity to whom the mantra is addressed is Savita, an ancient god of India.

Vishwamitra was a kshatriya by birth but became a Brahmin later (which was considered to be an achievement of the highest order those days, when money was not the yard stick) by chanting only the Gayatri Mantra. Therefore, even to-day this is one mantra that is taught without any exception to a Brahmin vatu at the time of thread ceremony.

Three Dimensions :
Gayatri mantra has three dimensions. The metre in which it is composed is called Gayatri, i.e. three lines with eight letters each and this is the smallest metre in the poetry of Rigveda and all other metres are the extension of Gayatri Metre with more letters and more lines. Therefore in respect of prosody Gayatri is regarded as the Mother of Prosody.

Lord Brahma's Consort :
Lord Brahmha, the Creator's consort is Gayatri and as she is supposed to be the Mother of Vedas, before one chants the Gayatri, one has to invoke her blessings. Here again Gayatri Mantra is regarded as the Mother of Vedas as the mantra is supposed to be the tiniest condensation of all the four Vedas. As stated earlier, the deity of the mantra is Savita who gives strength and energy to all the living beings from morning till evening everyday during the course of the sun.

Chanting :
While chanting Gayatri Mantra "Om" is prefixed and in addition to it there will be three more words, "Bhoo, Bhuva and Swaha" which are called "vyahriti" indicating, the Earth, the Firmament and the Heaven to suggest that the Lord Almighty is pervading all these three regions (worlds). In simple words, the mantra proper states, "We meditate upon the adorable glory and the brilliance of Lord Savita to stimulate our mental power of the highest order. "(Dhee shakti is supposed to be the greatest mental power any human being can think of, as it is the basis of enlightenment.) 

Lord Savita :
As we have already seen, the presiding  deity of Gayatri Mantra  is Lord Savita, who is closely connected to Surya the sun. While the Surya signifies the sun - the body visible to us to the naked eyes, the divine power behind it is not visible to the eyes and it is this invisible power  that is hailed and worshipped as Lord Savita. Rigveda says that he is visible in the form of the sun who is the giver and the sustainer of life on this earth and is a great friend of the people on the right path. While guiding, directing, controlling and supervising all the activities on this earth, day in and day out he is the bestower of every thing.Therefore we pray to him to stimulate our thinking  for the spiritual enlightenment that alone can bring  us everlasting peace  and happiness when all other worldly things can  not do it. Here is Lord  Savita’s message that has withstood the test of time:
   

Greatness of Gayatri : 
Gayatri is great only because through this prayer no wealth or earthly possessions are sought for like any other mantras. Incidentally while the first three Vedas have in them the sacred Gayatri Mantra, Atharvaveda does not contain it but there is a beautiful mantra addressed to Mother Goddess Gayatri that depicts that by chanting it regularly one will remain pure besides getting longevity, progeny, wealth, fame, health, happiness and the brilliance of and the lustre of Brahma. After granting all these boons Mother Gayatri will take the devotee to Brahmaloka leading by hand and present to the very Lord Himself. When we are taught Gayatri Mantra and when we know how to chant it, by spending a few moments in the daily routine, if we are going to get whatever we want, should we not try in this direction?
A Brahmin is supposed to chant the sacred Gayatri at least 10 times a day.

The following lines are reproduced from the authors' book "Gayatri" to amplify the meaning of Gayatri Mantra:

Present Status : 

For maintaining sanctity it appears this yajna is not performed in houses and they are being performed in temples. In the recent past on three occasions the yajnas have been performed in the temples:
a) From 18th Jan. to 22nd Jan. 1995, a yajna was performed in Haridwar under the auspices of Shri Kashi Math Samsthan, in Vyasashram on the banks of the River Ganga, with one crore chantings of Gayatri.
b) On 6th Oct. 1997, the second Gayatri yajna was performed in Shri Rama Mandir, Wadala, Mumbai, under the auspices of Shri Gokarn Math, as a part of their 9 days chain of yajnas.
c) On 16th Dec. 1999, on the first day of the Vishwa Saraswat Sammelan held in Mangalore under the auspices of the All India Saraswat Cultural Organisation, Mumbai. This was performed in Konchadi temple.

Can Ladies Chant Gayatri?
This is an oft asked question. Since it is a prayer seeking stimulation for higher mental power, the answer is definitely "yes". There should not be any doubt about it. But to be more effective they should be first initiated to chant but fortunately or unfortunately during the post Vedic period, ladies were deprived of having upanayanams and thereby they have lost for ever the right to receive the mantra. Still it is better if they know what this mantra stands for. In the upanayanam ceremony the Mother has a very big role to play as she is preparing her son to go to gurukula to receive the formal education when she herself was the first teacher to the child after the birth. Therefore she has every right to know what the child is going to learn. Then at least for two valid reasons the ladies are entitled to know the mantra. Firstly a married lady will sit as a partner of her husband during all the religious ceremonies except the ones associated with the funeral rites and rituals. Secondly, they as custodians of our culture can inspire the children to chant that mantra of mantras Gayatri, if they know its significance.