Well here's something I never knew. When you declare a table variable it does get instantiated into tempdb.dbo.sysobjects. I was under the impression it wouldn't. If you run this code...
declare @junk table(i int)
where name not like 'sys%'
... you can see it happening. I found this and a few other interesting table variable nuggets at INF: Frequently Asked Questions - SQL Server 2000 - Table Variables.