Very useful, with a little room for improvement. It'd be nice if after it was done auto-syncing it would go to the menu item you picked that triggered the sync (eg, Schedule). Also, the iOS people get the venue maps in their app, and the maps would sure be just as useful in ours too.
first time attendee - worked great I am/was a first time attendee to an IETF meeting. Worked great and saved me the trouble of hitting the website/printed schedule on every break.
* Synchronization to IETF 98 meeting agenda.