Hi all!
I seem to have trouble with Rhythm. I can never get it right for some reason. I can play lead and fingerstyle guitar no problem but is there any way I can improve my Rhythm technique?

Metronome. Helps a lot.
My Guitars
Squire Affinity Strat
Ibanez RG 350 DX
Fender Stratocaster MIM
Ibanez AEG20E
Tradition Guitars S2000F Pro
Almost all answers involving speed and control comes down to using a metronome and redoing it slowly.
There's a good chance that what I've written above is useless and if you take any of the advice it's your own fault.
Try to tap your foot to everything you play, as it should act as the constant underlying pulse. Basically train it to be a living metronome.

All the rhythm playing you do shall be independent of that. You may find to start with, that your foot will want to do the same rhythm as what your doing with your strumming/picking hand. Resist this.

Experiment with different styles of music. I found that delving in to Funk Rhythm Guitar Style improved my rhythm (and timing) immensely.

Also, practice developing 3 way independence, for example

singing a 16th note rhythmic terminology whilst...
clapping the eighth notes whilst..
tapping the quarter note pulse with your foot.

There are many rhythm books out there. The three way independence idea came from "Music Reading For Guitar - By David Oaks".

Edit - Lol, screwed up the edit there!
Personally, I nod my head when I play. Not a full-fledged bang, just a little nod. Little shoulder movement thar. What worked for me was playing over other bands' songs, getting a feel for their rhythm. Now it just comes naturally. I'm still not great with complex rhythms (7/8ths n stuff like that.) but on a 4/4, I'll never miss a beat. Ask me to play a lead, I'll just unplug, it sounds better. :P

It's funny as hell when you get it down and see another guitarist who thinks he's hot shit playing Eruption and pointing out his timing is whacked out to all hell, he denies everything and claims you don't know what you're talking about, you play it for him, he plays along with the song and realizes he's ****ing it all up. If fans are fish, lead is the hook but rhythm's the rod. Without it ya can't reel a damn thing in.

edit:: That 3 way independence gig is a wonderful technique to learn if you can. I've tried and have failed miserably, so I'll just stay away from it, but you might as well give it a shot and if you don't like quitting, don't.
Quote by fly135
Great list Rutch. On re-reading this one I'd have to say Solid State means not liquid or gas.

I figured it out.