An excellent meditation technique that I use when I'm feeling anxious is to sit down, and spend 10 seconds focusing on what I can see. Only my sight, and gradually increase my perception of what is around me right now. Take it all in, what else can you see.... Then switch to hearing for 10 seconds, and do the same thing, then to physical feeling (your weight on your chair or soles of your feet, chest rising and falling), and repeat for as long as you like.
The best thing about this method, is that you can do it while driving, while walking or while waiting in a line... or reading a web forum.
I love the calming feeling this gives me, and it centres me in the present moment.
Hope this helps.