I presented my first Prezi last week. I didn't make anyone seasick. The platform was excellent for what I was trying to convey -- a pretty non-linear project that took many years to evolve to a final product. I would recommend checking out prezi.com
My presentation was about the habitat mapping and time of year restrictions we have on Cape Cod and the Islands.
And see the Community Manager of Prezi give a TED talk about presenting.