There's a neat little thread on rpg.net that I thought would be fun here.
.Anyone with a copy of the new DMG and MM can play along.
How It Works: Take the first letter of the last word in the post above you (not counting signatures). Translate that letter into a number; A=1, B=2, C=3, D=4; etc. That's the level of your encounter.
Now, take the last letter of the last word in the post above you (again, not counting sigs). This determines the scenario of the encounter, per the following chart:
A,B,C,D,E :: Battlefield Control
F,G,H,I,J :: Commander and Troops
K,L,M,N,O :: Dragon's Den
P,Q,R,S,T :: Double Line
U,V,W,X,Y,Z :: Wolf Pack
So you've got an encounter level and a scenario. Pick some monsters from the MM and design an encounter!
Don't forget to include at the end some flavor text and tactics for the monsters