We decided to be honest with them from the get-go. How can they trust us otherwise? Also, they would think that it's ok to lie.
Besides, to us the real reason for Christmas has nothing to do with Santa Claus. I explained the legend of Chris Kringle and that its a great charity to others... but we don't tell the kids "you must believe (in this lie) or you don't get presents."
Same with Easter; has nothing to do with bunnies and eggs to us. I explained that some people celebrate Spring this way but it's not one of our celebrations. Besides most kids *I* have seen are SCARED of the guy in a bunny costume (and the guy in the Santa costume). And, how do you explain to them how Santa was at the Kmart 10 minutes ago and is at the mall now... and on the corner of "Main ST" on the way home? LOL
For the tooth fairy, my parents tried that junk. I never bought into it but enjoyed the quarter.
We get gifts for our kids many times throughout the year. SOmetimes for no reason, sometimes with their allowance (with mom kicking in a few more bucks), go to Busch Gardens regularly, go to Aquarium & zoo & park, etc.... I don't feel the need to make them believe in untrue things just to let them feel special.
You will know what's right for YOUR family. Whatever it is, don't feel pressure to do something just because "everyone else is". Do it because you can easily explain it to your kids.