Definitely You can and you should. But I think you can wait for a few more months for the cost of the SSDs to come down. Already there are Laptops there in the market with only SSD, and also as a support to the original hard disk ( which is only 5400 in speed ) . These supporting ones have only 32 or 40 GB capacity, wich will tremendously improve the speed of the machine
In the meanwhile please google 'HDDBOOST' or go to the following link
---read it well
I have this gadget with me. This is working in conjunction with a 10,000 RPM hard disk on my PC.
Without this it took almost three minutes for a complete system boot up.9with some 115 applications and almost 90% of them disabled in boot up). Now it is only about 35 seconds with all of them enabled
Dr. K. A. Rasheed