How do I make homemade Salsa thicker? I have been playing with homemade salsa for a few weeks now and I can't seem to figure out how to get that thicker tomato texture that a lot of southern Mexican restaurants have.

Right now I play with these ingredients:


Tomatoes
Onion
Jalapeño
Cilantro
Lime Juice
Garlic Salt/Cumin


This seems pretty basic stuff for salsa, but it has a pretty watered down feel no matter how I swing it. How do I get the tomato base that some of the classic salsas have in order for everything to hold on the chip a little better?

Update

I really wanted to accept two answers because I like both depending on what I am doing. For a fresh salsa (pico de gallo) straining the juice from the tomatoes seems to work really well. But for the thickness I was going for the key was experimenting with Tomato Paste/Cooking the salsa. I am able to get a much thicker salsa that I enjoy much more. I did learn how to create killer pico de gallo from this though.
Have you tried straining the salsa? Put it in a coffee filter or in some cheesecloth in a sieve sitting over a bowl. Let drain until the salsa's the texture you want.