imho, you can't go wrong with either camera so if the deciding gets too tough, flip a coin.

A few things to remember is that the SD800 is a newer camera so it has a few features not found on the SD700:
- slightly better high ISO performance,
- face recognition
- accepts Secure Digital High Capacity memory cards (not everyone needs them).
Though I don't own the SD800, I've added it to my blog as a 'wish list' item. You can read some pros and cons about both cameras at my blogs:
http://www.digicamhelp.com/camera-logs/Ultimately, you should make up your own mind what focal length serves you best. I would pick the longer telephoto lens over wide angle but not everyone feels the same.