For hiking, I use an Altoids tin. But in urban settings, I don't like the feel of that hard case in my pocket. For "around-town minimum", I just use a keyring with things attached.

For "general around-town" I found this one at Target for $3.99

http://www.caselogic.com/compact_camera_case/product_detail/index.cfm?modelid=57063

It's a soft case and fits in the pocket like a fat wallet. OK, pretty darn fat for a wallet, but it works well for me when wearing jeans. Just don't overstuff the thing and it sits nicely in a front pocket.