Ah, yeah a Memory upgrade would be great for your Mac, but if your Hard Drive is getting full that WILL slow it down a lot, so delete anything you don't need. AND ALWAYS ALWAYS ALWAYS keep 15% of your hard drive unused, so for every 100GB of space, keep 15GB unused. I did not do this with my eMac's hard drive and it crashed during my brother's Senior Project, it was a nightmare.