On Sunday morning and evening I held my nerve as I preached from Acts 2:33 on Jesus Ascended for my good friends at Reading Family Church. You can listen to the morning mp3 here: RFC Resources. I think the evening one was slightly better and a few minutes longer than the 30min first run.
The whole experience of going noteless has huge advantages - no lectern, no notes to look at, no need to break your eye-contact with people, no formality of words... and everything seems to flow better. The cost is sometimes a little lack of precision in language, though not much if you work at it and continue to love language and reading as I do, because really the cost is in much more preparation time, internalising the message and believing it... which is no bad thing! It means that what I preach isn't the transfer of my notes to the congregations notes, but rather a message that has affected my heart, held out to their hearts. The downside is it might be an excuse to prepare less and wing it, but if we take preaching seriously it'll require more preparation not less to go without notes.
Might not be the best way for everyone but I'm enjoying it.
Noteless preaching means you can't be complex (though that doesn't mean you can't have depth), you need a coherent argument - a story even - and you're going to benefit from really letting the text shape your message...
I'm still learning. How do you do it?