Android simulator on Eclipse eats HD

I've found that the Android simulator in Eclipse eats up my hard drive. I use an app to monitor my hard drive use, and I've found that when I start it up, it uses about 150MB of space on my hard drive while it's running. When I shut it down, I usually get that space back. However, if I have to close it due to it hanging or something else it will sometimes not give me all the storage back.

As an example, I was just using it and had to open 2 instances due to the first instance not working. When I closed Eclipse and closed all the instances of the simulator, I was not able to recover 100MB of data from the simulator. The simulator (and Eclipse) was the only application running on my computer, my computer was not connected to the internet for the duration of my use of the simulator (I had the Wifi card turned off), and this only happens when I use the simulator, so I doubt it's malware or a virus (plus I use a Mac, which makes it even less likely).

How can I clean up the disk space used by the simulator? My hard drive is not that big, so if it costs 100MB of space every time I use the simulator it will kill my hard drive very quickly.

Thanks.