I know they are very risky, but the potential gain is also very high. I always try and keep an eye for them.
Here is my pick for this month:

MDXO.OB

It is a new gold mine company. I received the email from those online penny stock pumpers. I usually ignore them, but this company announced a 5 for 1 stock split effective august 10, 2009. Usually, when a company announces a forward split, the price of the stock goes up. There are only about 2.5 million shares around and I could only buy couple thousand shares because my order could not be completed at the limit price. I will try later. 0.71-0.73 might be a good price to buy. Anything higher is a bit risky.

Warning: Usually penny stocks are pumped and then dumped. If you do not act in time, you end up being a bagholder.

Diclaimer: I am not telling you what you should buy or sell.