Set up a free account - and you'll have some options to configure. You'll need a Google search API key - there is a link in the sign up form - you also have the option of installing an advanced usage script on your own server - this allows daily updates of your data.
The keyword tracker allows you to track multiple keywords by domain, in other words, you can see where you rank for a given key phrase for any number of domains you (or your competitors) own. Simply enter the keyword and domain, and the system will show your rank on Google, MSN, Yahoo - or you can choose ALL to get your rank on all of the engines.
The backlinks tracker is simple - enter your url, and the system tells you how many backlinks you have on Yahoo for the single url, backlinks for the whole domain on Yahoo, and the backlink count on Google. The feature that makes both of these free tools really outstanding is the ability to track and graph your results over time. You simply set up a simple script and cron it daily, and your stats will be updated each day, with your progress, up or down, logged regularly.
The service even has a simple graphing feature so you can get visual graphs of your progress. All of this takes a couple of hours to set up, and then you can just forget about it - until you want to see your data. It's interesting to watch how your rankings go up as your backlink counts increase - a great way to validate that a linking strategy is working.
Try the DigitalPoint tracker - it's a great free tool.