Will SSD improve iPhoto and Aperture responsiveness? I have a late 2008 Macbook with Core 2 Duo and plenty of RAM and HD space. (8GB of RAM, max for my machine)

Every time I do some work in iPhoto and Aperture, my CPU usage goes up to around 60-80% eaten up by those apps. They weren't as responsive as when I was on Snow Leopard. This started happening since I upgraded to iPhoto '11.

I'm thinking of upgrading to an SSD, would that improve my iPhoto performance? I doubt it because it seems that iPhoto is CPU, not IO, bound. Has anyone else tried this?
The details you've provided aren't very clear.
1. Has this problem started to happen after upgrading to Lion?
2. What tasks in iPhoto are causing the slow down?
3. When it is running slow, how much free RAM does the system have? 

It's likely that it's slowing down because you're low on RAM