We just released last week a new database security monitoring and auditing tool. It's called Hedgehog, it is software only and host-based. It works by monitoring the shared memory for activity and acts on rules based on SQL statement, DB objects accessed, IP, User ID, application used and more. Based on the rules, the system issues alerts and also has the ability to automatically kill user sessions.
Apologies - currently it is for Oracle 9.2 and up, on Linux(RHEL/SUSE) and Solaris. A version that supports Windows, AIX and Oracle 8.1.7 will be out in a couple of months. Towards the end of the year we will support MS SQL Server. I hope this answers your question.
This information is on the website in the product pages. Perhaps I should make it more prominent.