Hastables, brings back fond memories, in mIRC Scripting Language I made lots of use of that if I had to store a LOT in memory, for instance the search results of .exe files on your C Drive. Basically you can think of a Hash Table as a MDB file loaded into memory, never touching the Hard Drive (unless it exceeds your memory limit and gets pushed into a swap file.

Hash Tables can seriously speed up things, given you have a LOT of things to store.