FATHER OF KONG:  I've been trying like crazy to get someone -- anyone -- interested in a story about Merian Cooper, the man who created King Kong.  He's one of the most fascinating characters in modern history.  He'd be great for a nonfiction article or a graphic novel.

MARS KIDS:  Too much young-adult and middle-reader fiction is fantasy (especially in the wake of the Harry Potter craze).  And most of what's billed as science fiction for younger readers is just fantasy with technobabble. I'd like to write some solid hard-SF juveniles about the first kids on Mars.

THE LONG COMMUTE:  At one time there were streetcar lines connecting cities from Maine to Virginia.  A fun bit of "stunt journalism" would be to travel from Boston to Washington entirely on commuter trains and city buses. If it can still be done...

MR. HOOKE:  I did my Bachelor's paper on Robert Hooke, the English scientist who was a contemporary and rival of Isaac Newton.  If he hadn't lived in the shadow of the Smartest Guy Ever, Hooke would be much better known.  I would happily work on a novel, story, or nonfiction piece about him.

BEN'S MEN:  A "technothriller" about secret agents working for Ben Franklin in Paris during the American Revolution would be a lot of fun, either as a novel or graphic novel.

 INTERSTELLAR:  For a while I've been outlining a comic book (or graphic novel) about humanity's first interstellar voyages, using a hard-SF approach. 

AGE OF ENLIGHTENMENT:  If a game publisher is interested, I think a roleplaying game or sourcebook on the 18th Century would be a fantastic resource and a blast to write.