From a question on Meta StackOverflow:
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.
