Google Docs

Just starting looking at using google docs for syncing/mobile/file access.
Most of my work has been in excel and was wondering if anyone had any tips trick or advice on how much its compatible with excel.

I'm sure a lot of the more complex functions and techniques used in excel wont be transferable but wonder what experience (if any) any one has had.

yea i DO use GOogle Docs, but I like Dropbox better overall.. and its pretty cheap too