Question: We need to migrate our database from MSSQL to Oracle and we have over 100 stored procedures written in PL/SQL TSQL. I know its a long shot, but has anybody ever successfully used an automatic migration tool to do the work? I've seen some tools on the web, but I have no way to judge their ability to handle various code. Any personal experience in the matter would help.

Answer: 
I would suggest doing it by hand. First, to me, personally, a 100 doesn't sound too bad at all. I'd bet that your development follows patterns - using getutcdate() instead of current\_timestamp, etc. This means, there probably are a few very repetitive problems that you and your team will be able to learn from. To me, this will hold the added benefit of teaching you PL/SQL nuances/extensions, which you'll probably need to learn in order to maintain / expand the new system. 

Good luck!
In the past I tried to do the opposite, but I'm afraid there's no 100% reliable way. Some features are unique to each RDBMS and can't be replicated by a tool (for example IDENTITY fields in SQL Server vs Sequences in Oracle). Considering that, at the end, I had to review each Stored Procedure to ensure it does what it's supposed to do, I realized it was better to plan a manual port and learn some PL/SQL while doing it.