I was recently reading Stephen Few's book entitled "Information Dashboard Design" and was exposed to many examples of the "bullet graph". While most of the examples show them being used to show sales type targets, it got me to thinking that they may be a good way to show actual time spent vs. the estimated time for a project in Klok. I found that there was no out-of-the-box component that met the specs that Mr. Few describes. So, I decided to put one together for myself. Here is a screenshot.
Granted, this could probably be made more configurable, but this is just the first crack at it. So, right now, you can set the label, target, actual value and give the ranges that would indicate "bad", "satisfactory" or "good". You can also specify how many tick marks should be shown on the quantitative scale.
Feel free to check it out here (view source is enabled) or download the zip here.
I highly recommend Stephen's book for anyone who is creating any application that needs to display complex data. You don't have to be building a traditional "Dashboard" put his suggestions to good use.