Hey Al! Good question... I too was looking for the same thing recently and ran into Rico, Sajax, JPSpan (Harry Feucks project) and a few others... but those three seem to be the most popular...

From what I've seen I believe Sajax seems to be the most mature project - with JPSpan following right behind. I still haven't had the chance to use any of the three - so I can't say for sure - but I spent hours going over all three of those... here's some links:

http://www.modernmethod.com/sajax/ ( Sajax )

http://jpspan.sourceforge.net/ ( JPSpan )

and it looks like you have Rico... Definately check out those two though - there's alot to think about but I think the three mentioned are the best!