If you travel with your baby, feeding them while you're out can be a bit of a hassle sometimes. Being set up to feed them no matter where you are is made easier by some modern inventions, though, and we'll help you get sorted out what you need versus what you don't.
The first thing that you'll need if you still feed your baby while he's lying in your lap is a nursing pillow. This makes it much easier to feed your baby when you're not at home, but you'll probably want an inflatable one. Pillows can be too bulky to take with you because they take up too much space, so inflatable is what you're looking for here.
A travel high chair is good if you're going to be in and out of hotel rooms and restaurants while you're traveling. Some of these can attach to a table, while others attach to dining chairs. You can go with your preference on these, but if your baby isn't big enough or stable enough to be trusted to sit on his own, you'll need one of them. these are the best.
The Tommee Tippee Travel Bottle and Food Warmer is something else you'll probably want to bring along with you. It's not expensive; at $12.56, it's a steal. It's not just a regular thermal bottle; the white top is for putting the bottle in and pouring the hot water into, so you don't have to scramble to find somewhere to put the bottle to warm it up.
A good diaper bag can't be understated here, though. If you're traveling a lot, you'll want a backpack-style diaper bag, especially one that has insulated bottle pockets. It should have plenty of room for you to pack extra onesies, extra bibs, and wash cloths, just in case you have to give him a wipe down later. Giving a bath on the go can be difficult sometimes, but travel baby bath tubs exist that are collapsible just for this purpose. You can see a few of those here: http://www.housemama.net/best-baby-bath-traveling/
As your baby gets older, you might want to consider packing them their own utensil set in your diaper bag to eat with when they're in public. They may enjoy having a special set of utensils just for them. They're generally available for under $10 and include their own carrying case.