Just giving you a heads up, 99% of the alt coins are a waste of time and do not fulfill the main concept of the digital currency concept.
Invest only in Bitcoin (
BTC) , it has more support and interest than any other coins(projects).
Although you might still find other projects with great support (either in great developers or they are heavily invested by many), like
Litecoin (which suffers from a few big holders that manipulate the price, but you might earn a bit of $ from it in the short range aka mt.gox announce to add it to their trading).
Do NOT count on MtGox adding Litecoin, they believe there's an actual need for handling thousands of transactions per second with their imaginary Midas engine. They also cannot handle this basic functionality called money withdraw, so there is no hope on adding another coin to the system.