Best sippy cup - any with air vent thingy?

[MilkyChops]

My LO is great with water out of the really basic style sippy cup but is too impatient to come up for air when drinking his milk, are there any with a vent type thing to let air in like on a bottle. Or does he just need to learn to come up for air when drinking his milk?

[silverstreak]

We use the tommee tippee active ones, one sports and one sipper; they are both super non-spill (so fine on the sofa!) and have air holes for good flow (with sucking).

[schmalex]

I've always just used the basic sippy cups. He probably needs to learn to come up for air - that's the difference between a cup and a bottle!