Thanks for your response kimsland, and the info about the asset.com/svctag.exe solution. If I could get my laptop to boot to CD, I'd give it a try. In fact, I might try using the "building a bootable hard drive" from the DST site in order to try it. My guess is that it won't help me though since the machine itself is locked, so it won't even try to boot off the HD. Any idea about this?
Anyhow, I actually have something to contribute. Do you happen to know if the service tags of an Inspiron 700m can be changed with the asset/svctag utility? If so, couldn't a user change their service tag to that of a service tag with a known master password... and reset their passwords that way?
There's a Russian blog I came across that had some listed service tag/master password pairs. If anybody out there's willing to give this a try, I'd be curious to know whether or not it worked. Change your service tag to one of those below, then use the corresponding master password to unlock your machine. Afterwards, you could revert your service tag back to its original value. Anyhow, these are from the blog:
service tag: 1234567—595B password: 46rg65ky
service tag: 1111111-A95B password: 2qhuvn1b
service tag: 1234567-D35B password: 5tc8q9re
Inspiron 700m: [1234567] password: 37897101