I've been looking for a case for my S95 for a little while. I found this guy on DealExtreme a little while ago and decided to try it out. I received it last week, and it's great. It's got a vintage/retro feel in brown leather with a snap case/cover that's actually quite impressive for a mere $10. The front cover is held on by three snaps, which you can pop off the sides to take a picture, or what I like most about this case is just leave this cover off altogether and use the camera with just the bottom holster & strap. There is a tripod screw built into the base which secures the camera and then you can go to town. The strap is not the most amazing quality though. If I was going to take a trip with this thing and rough it up I'd probably swap it out for a spare Canon camera strap. I have a cool 80s Rebel one kicking around somewhere. Unfortunately there is some Canon branding on the cover & strap which I wish wasn't on there, but oh well. Just know this is definitely not a genuine Canon product. It looks like you also have the option to get it in black as well, just search for 'Canon S90' case.
Just to clear up, both the Canon S90 & S95 will fit perfectly in this case due to their (practically identical) form factor. I have the S95, but like I said the Canon S90 is similar you should be able to use a case designed for either camera with no problems.
If you aren't familiar with DealExtreme yet, you should be. It's pretty amazing, I'll be posting a little writeup about they kind of things I order from them, which is to say a lot of things. Just keep in mind that anything from there, including this camera case, is coming straight from China, so don't expect it overnight or if you need things in a hurry you can usually forget about it. Typical ship times in my experience is about 2-2.5 weeks, which really isn't bad considering shipping from dealextreme is always free!