Sona si latine loqueris.
Honk if you speak Latin.

Te audire no possum. Musa sapientum fixa est in aure.
I can't hear you. I have a banana in my ear.

Vacca Foeda!
Stupid Cow!

Re vera, cara mea, mea nil refert.
Frankly my dear, I don't give a damn.

Sentio aliquos togatos contra me conspirare.
I think some people in togas are plotting against me.

Antiquis temporibus, nati tibi similes in rupibus ventosissimis exponebantur ad necem.
In the good old days, children like you were left to perish on windswept crags.

Caesar si viveret, ad remum dareris.
If Caesar were alive, you'd be chained to an oar.

Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
How much wood would a woodchuck chuck if a woodchuck could chuck wood?

Nihil curo de ista tua stulta superstitione.
I'm not interested in your dopey religious cult.

Recedite, plebes! Gero rem imperialem.
Stand aside, little people! I'm here on official business.

(At a poetry reading)
Nullo metro compositum est.
It doesn't rhyme.

Non curo. Si metrum non habet, non est poema.
I don't care. If it doesn't rhyme, it isn't a poem.

Minutus cantorum, minutus balorum, minutus carborata descendum pantorum.
A little song, a little dance, a little seltzer down your pants.

Tuis pugis pignore!
You bet your bippy!

Quomodo cogis comas tuas sic videri?
How do you get your hair to do that?

Feles mala! Cur cista non uteris? Stramentum novum in ea posui.
Bad kitty! Why don't you use the cat box? I put new litter in it.

Romani quidem artem amatoriam invenerunt.
You know, the Romans invented the art of love.

Aio, quantitas magna frumentorum est.
Yes, that is a very large amount of corn.

(At a barbeque)
Animadvertistine, ubicumque stes, fumum recta in faciem ferri?
Ever noticed how wherever you stand, the smoke goes right into your face?

Neutiquam erro.
I am not lost.

Solum potestis prohibere ignes silvarum.
Only you are can prevent forest fires.

Ita erat quando hic adveni.
It was that way when I got here.

Sic hoc adfixum in obice legere potes, et liberaliter educatus et nimis propinquus ades.
If you can read this bumper sticker, you are very well educated and much too close.

Hocine bibo aut in eum digitos insero?
Do I drink this or stick my fingers in it?

You can't say that in Latin.
Illiud Latine dici non potest.

Vah! Denuone Latine loquebar? Me ineptum. Interdum modo elabitur.
Oh! Was I speaking Latin again? Silly me. Sometimes it just sort of slips out.

As seen at http://www.zippynet.com/pages/latin.htm