Even though we use agile development at work, we still have to keep track of the time we actually spend on tasks for both cost accounting reasons and also so we can compare actuals vs estimates - and hopefully improve our estimating ability.

Web Worker Daily has a short little post on options for tracking time. It's fairly glib but has a few links to comparison lists for specialised time tracking applications. So, if you need to track time and your memory fails you from one day to the next (let alone a week later when you fill in time sheets) then have a look. There might be something there you find useful :-)