1. Open up VirtualDub.exe from the extracted folder.

2. Go to File >> Open video file...

3. Navigate to your Fraps folder and open up the footage you want to speed up. You can check
it's the right footage by hitting <Space>.

4. Go to Video >> Frame Rate...

5. Where it says "Source rate adjustment", change the FPS to what the current FPS is
multiplied by however much you want to speed it up. So if my current FPS was 30, but I
wanted to speed it up five times as much (as you say anything above four times is impossible
in Vegas), then I would change the FPS to 150.

6. Preview the footage again by hitting <Space>. It should now be at the correct speed.

7. Go to File >> Save as AVI...

8. Save the file back into your Fraps folder with something to distinguish it. Wait for
VirtualDub to render it.

You now have an AVI file at the correct speed. If you watch it you will notice that the clip
is jerky and the file size is huge (I got 1.46GB for a 17 second clip, much bigger than the
original Fraps footage). However, this does not matter. Just load it up in Vegas and edit as
normal.

When you're done, render to WMV. Without any editing to the 1.46GB clip above, I rendered it
to WMV in Premiere. The resulting file was 333KB.

Hope that helps you.