Speeding up iMac (early 2006
SSD will make everything feel faster, but it's kind of pricey. Your internal HD is probably wearing out anyway, so it's not a bad idea to substitute it. If price is an issue you can buy one of the new 7200rpm with 32/64MB of cache, and do a clean install. Before moving your data into the new HD, install your Applications. This way they will reside in area of the disk which can be retrieved faster.