save md5 generated hashes to the file ?

[rsberzerker]

No. If you want to waste your space with rainbow tables go to freerainbowtables.com.

To add an example, ophcrack has a paid NTLM rainbow table of all possible characters (?a equivalent) for only 8 character passwords. No 7 character passwords, no 9 character passwords, just 8 characters. The tables are 2TB in size.

While true that disk space is getting cheaper and cheaper, you still have to figure in file access times. With a decent graphics card, it can be faster to run oclhashcat than to search through the tables for a great many cases.

As I learn more about hash cracking, I'm becoming a believer in the philosophy that rainbow tables are obsolete, and pure brute-forcing nearly so.