Unless you are in the business of chip design/manufacturing, it is too late to get into Bitcoin mining. However, due to a rapid price increase in Litecoin, it's actually pretty profitable to mine them with an ATI GPU at the moment. On the order of $10-20/day per high end ATI GPU. However, this is only likely to last a couple days until the difficulty catches up to the price. If you have free electricity, you'll probably still be able to make a few dollars per day long term with litecoin, but not if you have to pay for it.