not at this time. This can be done in about an hour with Linux and Squid -- google for "linux transparent squid". Basically it's like this:
Install Ubuntu from a live CD
apt-get install squid
spend ten minutes on the squid.conf file (it's already set up for transparent proxy, you just have to set site-specific stuff)
modify your firewall to direct all TCP 80 traffic to the squid.
apt-get install webalizer or calamaris so you can get reports from your log files.
As an added benefit, you'll improve your user's internet performance by a few percent. It used to be a huge performance boost, but these days every web developer thinks their site is too special to be cached At the very least, graphics will be served locally.
If your in the market for a new appliance, we just put in a Blue Coat appliance and it works great for content based filtering, reporting, and AD integration.
I'm not sure if LANDesk will make this a part of their business or not. In my opinion internet usage auditing is probably going to be best handeled by an appliance sitting at your route out to the internet. For something to be agent based it would require almost real time reporting of traffic at the client back to a central database, and this could cause a lot of traffic on your network for this reporting to happen.
Hope that helps.