We decided to go to Disneyland at the last minute and the only camera I had with me was my 5D. Way too much camera to be lugging around on rides. We stopped somewhere and I bought the SX110. Not quite pocket sized but a seriously nice little camera. The 10x optical zoom kicks some serious butt over the standard 3x and 5x found in many smaller P&S's. Also an ISO of 3200 to work in those dark, dark situations where flash is just not appropriate. The only downside that I've found personally, is that this camera sucks AA batteries dry like you won't believe!
Can't say that I have any first hand knowledge of the other two cameras that you mentioned.