One site that I like to get quite a bit of stuff from is
http://www.freecabs.de - the upside to that is that it is designed for the ppc screen. Though of course there are lots of free ppc program sites out there, just use google - it's your friend.
Ah, I do assume that all of the apps on freecabs are legal - I have only checked the games out. But, as I did find it from HTC's own mobile portal I would imagine that they are all legit.