1. Go here.
2. Play around until you get a list of pairings you'd like to see (or at least want to use to torture unwilling captives). [ed. I cheated a bit on this, reloading the page a bunch of times and picking and choosing from the results -- most of the lists had too many characters from anime fandoms that I know literally nothing about.]
3. Check out my list below. Write a drabble for one of the pairings in the comments. Make it as ridiculous or implausible as you need to.
4. Post your own list in your journal, and I'll look it over and write a drabble for you.
Dave Kovic (Dave)/Mayor Wilkins (BtVS)
Peter Pan/Jack the Ripper
Crow T. Robot (MST3K)/Garibaldi (Babylon 5)
Feyd-Rautha Harkonnen (Dune)/George W. Bush Jr.
Little Red Riding Hood/Gippal (Final Fantasy X-2)
Quark (ST:DS9)/Randall (Clerks)
Gilderoy Lockhart (Harry Potter)/Dawn Summers (Buffy)
Jean Valjean (Les Miserables)/Alex Krycek (The X-Files)
Cassandra (Greek mythology)/The Corinthian (Sandman)
Dolores Umbridge (Harry Potter)/Nanny Ogg (Discworld)
Pac-Man/Johnny Damon (The Boston Red Sox [ed. - former])
Bono (U2)/Col. Flagg (M*A*S*H)
Captain Barbossa (PotC)/Dr. Scott (Rocky Horror Picture Show)
Moses (Biblical)/Jonathan (Buffy)
Thundarr the Barbarian/Deanna Troi (ST:TNG)
Kaylee (Firefly)/The Emperor-Beyond-The-Sea (Narnia)
T.J. Hooker/Sophie (Howl's Moving Castle)
Kristine Kochanski (Red Dwarf)/Scarlett (G.I. Joe)
Agent Dana Scully (X-Files)/Aragorn (Lord of the Rings)
Lorelei Gilmore (Gilmore Girls)/Duncan Kane (Veronica Mars)
Mrs. Coulter (His Dark Materials)/Fairy Godmother (Shrek 2)
Neville Longbottom (Harry Potter)/Ford Prefect (Hitchhiker's Guide To The Galaxy)
Oskar Schindler/Ace Rimmer (Red Dwarf)
Phlox (Enterprise)/Neelix (Voyager)