Currently have no lenses for my 30D and just spent most (all?) of my money on a new scope. Looking for a cheapish prime that's wide enough to take family snaps but will also serve for widefield astro shots. The Canon 28mm f/2.8 or 35mm f/2.0 seem nice. Tried the 50mm f/1.8 in a store and it's a decent lens but fov just too small for family stuff.
Will also consider the kit zoom lenses if you have one lying around.