From [a question on Meta StackOverflow][1]:

> You can "bump" your thread by
> providing status and progress updates
> resulting from your own continued
> efforts to answer the question
> yourself. I usually do that unless I
> really hit a dead end with no further
> clues to follow. Some times I
> eventually bring about enough
> understanding to realise the answer,
> and thus post a resolution to my own
> problem.
> 
> If you have at least 75 rep points,
> you can offer a bounty, promising to
> give some of your points to the person
> who correctly answers your question.


  [1]: http://meta.stackoverflow.com/q/7046/152101