Does anybody still play Splinter Cell double agent multiplayer? if you do send me a message or something, cause i see no one online.

No.

Yes, a few people still play. Not many, though, and not at all times of the day.

It's hard to tell how many people play Double Agent, because they don't have a good lobby--or a lobby at all according to what I've heard. There's no counter to see how many people are playing like you have with Chaos Theory.
If it helps your worries, go to Youtube. You find a lot of people have made montages or music videos while playing the online features (Blackballa and JagoTag to name a few).

I feel the same way, i can find anyone online. I guess it is just me and you buddy, friend up.

Now more people play it.
Take a look for some clan websites, there are contact with clan members.
http://www.phili-sc.de/5.html - UEF
http://gefclan.infernohost.net/ - GEF_
http://www.tec-squad.de.tl - T.E.C
http://satansservants.piczo.com - .SS