The gang at XDA-Developers are hard at work on a full port of Counter-Strike to Android devices, but they've already released two playable versions Android owners can run right now.
The video above shows Counter-Strike being played on a smartphone (using the game's Matrix mod) and a tablet. It appears to have variable touch controls -- although I could be seeing that wrong -- and appears a little sludgy to control: notice how many rounds he fires (touching the rifle, to do so, apparently) before bringing someone down with a head shot. However, if you have Sony's Xperia Play, well then you also have a gamepad, and now the experience becomes a little more intuitive.
Still, it's Counter-Strike. The port is being built with Unity, will support multiplayer and can be downloaded with either Facebook or Kongregate versions available. There are two versions out there, one for devices running Android 2.0+, another for those running Android 2.3 and up. (See the XDA-Developers thread for links.) That means it won't work on anything with an earlier version of Android.
Counter Strike Now Available On Android Via Unofficial Port [RedmondPie, thanks Tanishq D.]