So I was looking over the code today as well as the beta announcement and wondered what your favorite existing OnTime feature is, as well as (if you're using the beta), what your favorite new feature is.
I think my favorite new feature is the multi-editing capabilities (and not just because I wrote them ;)). It's an excellent time-saver, and I really like how it's implemented in the web version (although getting FireFox and IE code to exist peacefully is quite an endeavor).