You do know that these passwords are much more secure than the LM hashes stored in the SAM file, for starters each of the cached hashes has its own salt added which will make them much more time consuming to crack. I do not know about rainbow tables but they can at least be cracked using John the ripper, here is a good tutorial on this from Irongeek:have read about "CacheDump" tool, which will get the hashes for the last 10 logged in users (something called MSCash), and have been able to get the hashes. However, seems that these hashes cannot be cracked using rainbow table, as they came in the following format:
http://www.irongeek.com/i.php?page=security/cachecrack



