Side by side layout sounds interesting; do you mean putting the activities next to the timeline?
So far, this has definitely been "design by developer"; so feedback regarding the interface is most definitely welcomed.
Re:Ask HN: Review our startup - EventGel
by mrduncan on Thursday October 15, 2009 @02:02PM
(#883887)
Since you mention that it's been developer designed - Ryan Singer of 37signals gave a really great talk at WindyCityRails on how developers can build better UIs that you might want to check out: http://windycityrails.org/videos#4
The logo / menu / page title instantly create some confusion and clutter. The timeline doesn't look too user-friendly either.
I'm just commenting on the interface though, I haven't looked at the functionality too much yet.