You can upgrade the hard drive and the memory on it, but it's going to require opening up the iMac and because of the CRT inside, might be a risky. Wait until the end of this week for any announcements on newly released Macs (something that's rumored to happen during MacWorld this week). If new machines are released, try and get one of those. If not, then I would look at something like the Mac mini as a replacement machine, or an iMac G5 if you have the money for it. The nice thing about that Mac mini is that it's affordable and if you decide to get one of the newer Intel based Macs later this year (if they aren't released this week), you can still afford to do so. Not that this will make the current lineup obsolete (it won't for a while), but you'll have a much snappier system once the new Intel Macs come out.