SSD is it worth it?

Hey guys,
I've been looking at some SSDs and I was just wondering would I see a speed increase if I put one in my laptop (Macbook, Early 2008 model). I suppose anything would be a speed increase because its horrendously slow booting and loading apps, but I understand that SSDs are Sata III and I'm positive my Macbook doesn't have that. I'm also looking for one in my desktop, I would get full effect from the SSD here because my mb has Sata III.
So just wondering if either computers would benefit

Regards