Akshay Tritiya

The word "Akshay" means the never diminishing in Sanskrit. It represents eternal prosperity for any new beginnings made or valuables bought on this day

If you have something to be started, and esp want that it should be prosperous, and be with you ever... do it on Akshay Tritiiya (fallling on Apr 19, 2007 this year).

The most auspicious day for marriages - if there is some fight on, esp due to kundlis' mismatch, then just trust Lord Vishnu and go ahead with the marriage. This year Abhishek's and Aishwarya's marriage is hence taking place on Akshay Tritiya.

Kanya daan, Vidya daan, and akshat (rice / ann) daan are considered to yield many-fold benefits.

Akshaya Tritiya day is the very auspicious day - there's no inauspiciousness to be found today so even checking muhurthas is considered unnecessary, so auspicious it is. Whatever one does for devotees, and for Krsna that person will get more benefit and it is eternal benefit and never lost.
Links:
http://en.wikipedia.org/wiki/Akshay_Tritiiya
http://www.salagram.net/parishad66.htm