Check this out - especially Chapter:6

http://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/sql/maintain/operate/opsguide/default.asp

Similar reply like other did - Use CASE statement. Check out the link - Vyas has a nice example.

http://vyaskn.tripod.com/programming_faq.htm#q2

Another nit-pick detail that contributes to improvement of the performance is that a table variable requires less locking and logging resources as the transactions involving table variable last only for...

If you are using temp table inside a stored procedure there is an advantage using a @table instead of #table. The stored procedure will spared with the recompilation each time...