Should I let the cat drink from my water?

So I tweeted:

i've been drinking out the same glass as the cat for years and nothing bad has ever happened to me

My friend Travis (travisformayor.eth) said I should put this to a poll, see what the holders think.

Should I allow the cat to drink from my water cup?

Note that this will also affect whether I allow the cat to lick the top of beer cans, which she likes to do. my cat likes beer.

(previous cat poll: Can the cat go on the counter?)