Prior to asking on the Lab board - Where can I find....?
Please do the following, go to -http://findchips.com/avail
and enter the full or partial Part#
It will search for any component (not just chips) among over 20 distributors, including the 'usual suspects', including mouser, allied, newark, digikey, plus many others that you might not be familiar with. Often these vedors will also provide links to data sheets. This is a great resource.
If you are looking for semiconductors, including out of production chips and semis, I have found these 2 vendors to have extensive stock and excellent prices -http://www.matchaknob.com/
You'll have to establish an account with them and communicate via fax. They do not like phone calls. A bit eccentric, but an excellent vendor.
A bit easier to deal with (they take phone orders)-http://www.bdent.com/
If you have lots of time to peruse what is available in the surplus/excess-stock market this link provides great links -http://www.eskimo.com/~billb/supliers.html
I will add suppliers of 'audiophile approved' components in the future.
I'm going to lock this thread to keep it compact, but if you'd like to see specific vendors added, please PM me.