what can you bring back on plane?!?

Meat is basically the only thing you can NOT bring back (well, not fruits/veggies or plant products either). Not even shrink-wrapped or dried or cured. I'm sure people have sneaked it in successfully. I didn't even try. And the dogs were a-sniffing when I landed at LAX so I'm glad. Cheese is OK if you shrink-wrap it and if you are going somewhere famous for its cheese (which would be almost anywhere in Italy), it's certainly worth it. I went to a dairy outside Parma and 26-month Parmigiano was about 1/3 the price here. I am still nursing my chunk more than 6 months later, I hate the thought of using it up, it's so much better than what you can get here, even the expensive/good stuff. I bought my parents a chunk of Pecorino Toscano in Pienza, and they said it was THE best cheese they've ever had.

I have brought back both pasta and olive oil. Oil is much easier if you get it in a metal tin, but I have successfully brought glass bottles back, too. I've never brought wine myself, but a lot of wineries will pack your bottles in luggage-friendly packing.

Depending on your level of foodie-ness, I would definitely recommend bringing pasta. I saw shapes in Italy (primarily Emilia-Romagna) that I had never seen before. I love taking leftovers to work and showing off my gramigna and garganelli. I wouldn't bother bringing tomato products back because San Marzano tomatoes and paste are so readily available in the US.

You could bring back balsamic, but if you're not going to Modena, buying it somewhere else in Italy would be the same as buying it in the US I suppose.

One of my favorite things to bring home, though, is OLIVES!! No problems at customs, no refrigeration needed, no checking necessary if you drain off all the brine, and there are a ton of varieties there for reasonable prices that you can't find in the US, at least, not that I've found.

wine. Packed it well in my checked luggage. yummy.

Just remember, any liquid item over 3.4 ounces must be put into checked luggage. If you're only doing carry-on, keep this in mind.