Our favorite cloud service has managed to hit 100 million users in just four years. Dropbox is celebrating the milestone with a contest.

Writing in the company blog, Dropbox cofounder Drew Houston recalled how he came to the idea to create a cloud storage outfit.

“Dropbox had its humble beginnings in a Boston train station when I forgot my USB stick at home,” Houston wrote. “We’re still unsure if it was fate or fluke, but one thing’s stayed the same all these years: each of us has a unique reason for using Dropbox.”

Personally, I think he did not forget his USB stick. He was robbed by the Dropkick Murphys and/or Denis Leary.

In any case, if you have an interesting Dropbox related story to tell, write it up and enter the contest. Dropbox is offering 100GB of storage for the top ten entries, while the next best 100 stories will get 10GB each.

You can enter the contest here. No vampire stories please.