Excerpt taken from: http://tafkac.org/faq2k/stupid_195.html and http://www.cs.uu.nl/wais/html/na-dir/folklore-faq/part3.html

Brushing Up
Debunked: Tourists' room is burgled, later finds snaps of "toothbrush up thief's ass".

Often told of tropical areas (e.g., Hawaii, various countries in the Carribbean, but there's even one for Colorado and Paris).

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Excerpt taken from Maxim Online http://www.maximonline.com/entertainment/articles/article_1296.html

A couple honeymooning in Jamaica find that their hotel room has been broken into—but nothing is missing. The rest of their trip is great, and they can’t wait to develop their photos. When they do, they see a shot of a grinning Rasta in their bathroom—with the wife’s toothbrush stuck up his ass.

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And the best version yet...
Excerpt taken from: http://urbanlegends.about.com/library/bltail.htm

A travel agent friend of mine swore this happened to her clients, but it's got all the signs of an urban legend (not only crude, but racist to boot):

A couple from suburban California were vacationing in Jamaica when their room was broken into and everything stolen, with the exception of their camera and their toothbrushes. Considering themselves fortunate to have retained the camera with their vacation photos, they returned home where they had the film developed.

Two pictures were unidentifiable — something like an aerial view of two mounds of dark earth with a pole in between. They later realized, to their horror, that it was a photo of their toothbrushes up someone's rear end.

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The first time i heard this legend, it was told to me by an old roommate who said he saw James Woods on Letterman telling this story. Google searches result in nothing relevant.

My toothbrush goes everywhere with me. I don't even trust my family.