I use an Ameda Purely Yours electric breast pump. I got it on Ebay (new in box, never used) for half the price it retails for. It works great for me (I don't have issues with milk production. Use a hospital grade pump if you need help producing milk). It pumps both breasts at once. In less than 5 minutes I can have two bottles full. I pump regularly and freeze milk for when I leave my baby with a sitter or my husband. You can adjust the suction strength and the speed on the pump and mine came with a power cord that can be plugged into the cigarette lighter so you can pump while driving, which is awesome for long trips. It also takes batteries.
Also, I used to find nursing in public difficult until I got a Hooter Hider (also known as a Bebe au Lait), which has made ALL the difference for me. H's their website http://www.bebeaulait.com/use.html They cost about $35 and are a wonderful nursing cover. I tried a generic brand and it didn't work well at all (the neck wouldn't stay open so I could see my baby), but the Hooter Hider stays open so you AND NO ONE ELSE can watch your baby nurse and have the bonding eye contact. And they can't fall or be kicked off by the baby. I give them as gifts to all the baby showers I go to. I absolutely love it. Breastfeeding is important to me, and I'm all for anything that makes it easier. I was uncomfortable nursing in public until I decided that other people could just accept the fact that I'm providing nourishment for an infant in a beautiful way. I try to make others as comfortable as possible, though, by covering up with the Hooter Hider.