Percentage of Flash / Java users

http://www.adobe.com/products/player_census/flashplayer/

Java Applet Example

flash games vs. Java Games

Flash games look cooler.
Which is faster?

Sockets?

Can I, over the internet, and/or by using ethernet cables directly, connect two computers to play an online game? (or so something that would need the responsiveness like an online game would)
can I do that with flash using sockets... or with java. How would I set up a server that did that?!