It's hard to believe that SQL injection is still an issue. My friend Zain Naboulsi gave us a great overview of basic security hacks and how to defend against them at our last MSDN Express event. I recall learning about SQL Injection issues over 12 years ago in my first job.
Here's a fairly decent article about some of the details of SQL Injection, in case you're not familiar with it's problems.
http://www.sqlservercentral.com/articles/Security/updatedsqlinjection/2065/