I personally think that the Eye One Display 2 is the way to go and it really isn't that expensive, when you consider the amount of money that people spend on cameras, lenses and other accesories only to throw it all away by not working in a colour managed workflow. I've been using a Monaco Optix XR for a few years now (it was essentially the precurser to the Eye One Display 2 and is now obsolete) and have no complaints with it and it's made a huge difference to my work.
The one thing to keep in mind is that pretty much all monitors have their brightness set far to high when you first plug them in and use them and this can really screw things up for you big time.
- Thorsten.