Do you always take your DSLR all the time?

Check out the Nikon coolpix P7700.

To me is it like the little brother to my D5100.

Very nice images - very sharp. The ISO performance is not quite as good as the D5100 but it is an acceptable substitute.

Here is shot I took in very poor lighting at ISO 800:

http://forums.dpreview.com/forums/thread/3346937

Fully manual controls (actually better control setup than the D5100, IMHO).

Best part is that I can fit it in a pretty small lowepro bag that goes on my belt.

IMHO, if the camera was good I don't think I would stick it in a pants pocket where it is likely to get damaged.  This camera will need a jacket pocket but again I would not put it there anyway - the belt bag is small and easy to use.

If you get the G15 realize the zoom is like only 140 mm, but the P7700 has 200 mm zoom and image quality in many reviews as good or better than the G15.  Based on this, I think the P7700 is a better choice if you want to best simulate multiple lenses on the D5100.

I hope this helps,
Juggernaut