To cure the beachballs, install http://www.clicktoflash.com/. You'll wish you had installed it ages ago.
Memory is cheap, and 1 gig is hardly all that much for photography related things. Two 1 gig DIMMs costs about $70 USD these days, and it'll save your hard drive some wear.
If you're not already running 10.5, then upgrading to 10.5 would give you Time Machine, but regardless moving to two 500 gig mirrored drives is always a good idea. We're an Apple value added reseller where I work, and we configure all towers to have mirrored system drives. Even our old dual and quad G5s have mirrored 2 TB drives.
I have yet to see an adequate thin client solution. It'd probably be easier to get a really long digital video cable and a USB 1 extender (you might be able to find a decent USB 2 extender, but the ones I've seen have been pretty flaky). Straight DVI cables don't extend very long, but if you get a long HDMI cable with an HDMI to DVI adapter on each end, you can go very far. I've used cables up to 100' without problems.
Memory is cheap, and 1 gig is hardly all that much for photography related things. Two 1 gig DIMMs costs about $70 USD these days, and it'll save your hard drive some wear.
If you're not already running 10.5, then upgrading to 10.5 would give you Time Machine, but regardless moving to two 500 gig mirrored drives is always a good idea. We're an Apple value added reseller where I work, and we configure all towers to have mirrored system drives. Even our old dual and quad G5s have mirrored 2 TB drives.
I have yet to see an adequate thin client solution. It'd probably be easier to get a really long digital video cable and a USB 1 extender (you might be able to find a decent USB 2 extender, but the ones I've seen have been pretty flaky). Straight DVI cables don't extend very long, but if you get a long HDMI cable with an HDMI to DVI adapter on each end, you can go very far. I've used cables up to 100' without problems.