IMHO the S2 and S3 are priced too high when you consider the features and the alternatives. If I were in your shoes I'd go for the D70s. It's an excellent entry into the digital world. The only fault I find in it is that it has no original grip. Sorry. I'm a bit anal about this, I will never by a camera without a grip. Then again, when considering its price and the fact that there are some third party grips, I'd buy it without hesitation.
Happy shooting,
Yakim.