I have a t30 and its brilliant, v.small but great images. 🙂
I bought it when it was first released so i'm not sure where the best prices would be now.
I played with a t50 at costco and found that the touchscreen is very weird - they whole black plastic on the back is touch sensitive, so touching the edges of it while holding up the camera means other presses aren't registered.
IF the specs are no different, get the t30, it's much better to have tactile buttons so when you are familar with the cameras controls, you dont have to look at it each time. Verify the specifications first 😉 .