I have now submitted 3 talks to YAPC::Europe. I'm not expecting all 3 to be accepted (I'd be scared witless if they were), but at least one of them may get to be a lightning talk should it not make the first cut.
My only worry is that lightning talks last just 5 mins. To some that's an age. To me, blink and I'll miss it. I regularly over-run at tech meets, but then it doesn't really matter. At conferences I have to be resourceful and include loads of links at the end, for everyone to go and find out about the extra info that I didn't get around to. In a lighning talk that just looks bad.
I like Nick's idea of participation lightning talks, although mine doesn't need physical participation. I also like Leon's idea of no slides lightning talks, although I'm not the most animated speaker, so looking at slides would improve that ;) I guess I'm going to have to be a bit minimalist, and go with 3 slides: hello, this is it, goodbye. Maybe I could stretch to 4. The 20 minute version will be easier as I'll have loads of examples to go through and a few graphs. I'll have to see what gets accepted though :)
I've also submitted 2 of the talks to YAPC::NA, so hopefully I'll get to practice one of them before Braga.