If you’re after a free helpdesk solution, give Spiceworks a shot. It seems to be targeted at smaller companies with under 200 users.

It currently sports:

• Helpdesk
• WMI-based asset tracking
• SNMP discovery of devices
• SSH login to audit *nix boxes

My only gripes with it at the moment are:

• A bit slow
• No updates sent to owner of tickets when the user replies (coming in V2, June 07)

The auditing features and functionality are mostly on par with the Open Source project Open-Audit, although Open-Audit does some things better, such as License Key retrieval, ease of viewing data.

Spiceworks is a closed-source project which is supported by sponsored advertisements on the right-hand side of the screen.