Here are some words and phrases in Latin that are the basic equivalents of English curses. Of course, the curses of the people who actually spoke Latin as their first language were much more involved and clever. IIRC, quite a few of them have been found as graffiti on the walls of ancient cities like Pompeii. Unfortunately, I can't find any information about those at the moment. If someone knows more about it, please add a writeup or /msg me. If you're feeling like including these in your supply of curses, make sure you're pronouncing them correctly!.
tua mater - Your mother
stercum! - shit!
futue te! - fuck you!
futuite vos! - fuck you! (to more than one person)
i futue se - go fuck yourself
canicula - bitch
irrumator - bastard
flocci non facio - I don't give a damn
cunnus - cunt
asinus - ass
tace! - shut up!
leno - pimp
meretrix - whore
arde in regnum phasmatis - burn in hell (literally "burn in the realm of the dead")
abi - go away
On a reccommendation from teleny, here's how to cuss out God, courtesy of The West Wing.
gratias tibi ago, Domine. haec credam a deo pio, a deo justo, a deo scito? cruciatus in crucem! tuus in terra servus, nuntius fui; officium perfeci. cruciatus in crucem. eas in crucem!
=
Thanks alot, Lord. Shall I trust this from a God of Righteousness, a God of Justice, a God of Wisdom? Your punishment to the Cross*! I was your servant on earth, your messenger; I did my duty. Your punishment to the Cross. And you to the Cross!
*literally "torture onto a cross", basically "go to hell".
Here are some from non3ntity, the final of which actually was on a wall in Pompeii.
imanis metula es - You're a big prick
Lahis felat a.II - Lahis gives blowjobs for $2 (substitue whatever name you want for Lahis)
Cosmus Equitaes magnus cinaedus et fellator est suris apertis - Equitias' slave Cosmus is a big queer and a cocksucker with his legs wide open
Sabina felas, no belle faces - Sabina, you give blowjobs, you do no good. (note that, since this is grafitti, it's misspelt)
| 
