Sometimes, you may be able to open .asd, .wbk or ~wrl####.tmp files by simply changing the file's extension. Often, renaming the file will not work, and opening it in Word will result in the following error:
There is a Microsoft article written for opening ASD files located here:
http://support.microsoft.com/kb/827099. It didn't work for me.
Another solution is to download, install OpenOffice.org, and use Writer to open these files. That solution works, however it requires installing additional software which can take a while. I'm not a big fan of installing applications to resolve a one-time problem. Also, installing software may not be an option for you at all (if you're using a work computer, for example).
I came up with another solution that I haven't seen posted anywhere. Basically, the trick is to create another autosave file, and swap your file with it. When you re-open Word, your document can be "recovered". Here's the step-by-step:
1) In Word 2007, click the Office Button, and select "Word Options"
2) In the "Save" Section, change Autosave time interval to 1 min, and also note the location of autosave files. Click OK.
3) Type some text in a new Word document. I don't think Word autosaves blank documents, so don't skip this step.
4) Using Windows Explorer, open the folder where Word autosaves documents (you got the path in Step 2). Wait for Word to create a new autosave file. This should not take longer than a minute. Hit "F5" to refresh, if it's been longer.
5) Crash Word.
A. The easiest way to do this is by opening Task Manager, and selecting "End Task" on Word.

B. Word will ask you whether you want to save changes. Select "Cancel".

C. You will get a prompt asking whether you'd like to terminate Word. Select "End Now".

D. If Word attempts to restart, click "Cancel".

6) Replace the autosave file with the file you're trying to open. Rename a copy of your doucument to match the recently-created autosave file. Copy the renamed file to the autosave directory, overwriting the recently-created file.
7) Open Word and it will ask if you want to recover Document1. That's your file!