Overclocking can be helpful if you have a computer that you're going to upgrade/replace soon, and you want to get one last blast of performance out of the parts that you already have (it certainly helped me. I had a p3 450MHz and an S3 Savage4. 'nuff said). It can also help if you want to get (as someone else mentioned) 3200+ performance out of a 2800+ processor due to financials. The inherit dangers of overclocking, however, are that it can significantly reduce the life of your parts if you overclock severely. It also demands better cooling. If you can afford the faster parts, then it's definitely a better idea to buy them, but if you can't, overclocking offers similar performance at the cost of the life-span of a cheaper part.