HasGeek Funnel is rather popular with tech events in India, with many events using Funnel or something very similar. Installing it yourself can be daunting however, as it's hard to get it up properly and keep up with the changes.
Which is why we're turning it into a hosted service anyone can use, at talkfunnel.com. We're going to adapt Funnel into Talkfunnel and put out an early release this week.