See http://polleverywhere.com/
Alan Hecht, former eLSS from Abington, let me know about this. According to Alan:
It even lets you download a PPT slide that you can embed in a lecture slideshow and will update instantly as students vote.
I'm (Alan Hecht, this is) in talks with them on pricing and other issues. Yes, students have to pay SMS fees, but a faculty member can decide to use it for just one lecture and not have to have students buy keypads.
See what you think and post your thoughts here!
WebClicker app for iPhone
I saw this demo'd at NMC last week. Looks pretty cool.
http://www.iclicker.com/dnn/OurProducts/webclicker/tabid/156/Default.asp...
Their classroom clicker is also pretty nice. S/W can be run right off a flash drive (supplied) without having to install it.
http://iclicker.com/dnn/OurProducts/Software/tabid/154/Default.aspx
So wicked cool!
I just tried this out on my Mac, using their DeskBar:
http://www.polleverywhere.com/polls/NjQ0NTg3NzAx/macdeskbar
and the service looks like it works wonderfully. It's fast and easy. The free account could even be used with classes with slightly larger than 30 participants - a race to get your vote in.
UPDATE: I was even impressed with the 280slides.com service. I've only had a cursory look at it. I'm later going to try to embed the flash SWF for the poll into an Adobe Presenter file since you can import SWF files I believe.
Thanks for sharing!