The FZ's are very good megazooms. And it will be a great little travel camera to go along with the XSi. Just keep the iso at 800 and below and you will have very good results.
The FZ35 is at a all time low in price. So that can save you a bit more money.
Super Frequent Flyer, no joke. Ex Patriot and loving it.
Canon Eos 60D, T1i/500D, Eos1, Eos 630, Olympus EPL-1, and a part time Pentax K-X shooter.