Baking: Baking potatoes on the grill is very easy and requires virtually no intervention. To protect whole potatoes from the intense heat of the grill and so help them cook evenly, wrap in aluminum foil. To get the most flavor out of a grill-baked potato add a little something to the packet. Start by taking a piece of foil large enough for your potato. Pour about a tablespoon of oil in the center. Season with salt, pepper, herbs, or whatever you like. Place the potato on the oil and wrap it up. The oil will move around the potato while it cooks, keep it moist and the seasonings will add flavor. Place them anywhere on the grill that isn't in the way. If you need your grill really hot it is best to place them away from the high heat, like an upper rack or off to the side. Baked potatoes are done when a fork pierces to the center easily. Baked potatoes will take about 45 minutes to an hour to cook.
Slicing your Potato: When grilling potato start with slices thin enough to cook quickly but thick and large enough to keep them from falling into the fire. Typically you can do this in two ways. Wedges are made by cutting the potato in half lengthwise, then cutting that half into 4 to 8 long thin wedges (depending on how big the potato is). These are easy to work with and won't fall into the fire if turned perpendicular to the cooking grate. Slices are perfect for packets. A good grilled potato slice should be about 1/4 inch thick (little over half a centimeter).
Wrapped up in pieces: By cutting up potatoes into thin slices or wedges you can get them to cook much faster. It is best to keep the packets relatively small, so if you need a lot of servings you might want to wrap up the potato pieces in groups. Take sliced potatoes and place them on a sheet of foil large enough to wrap them up. Top with olive oil, balsamic vinegar, herbs, seasonings, bacon pieces, chopped onions, bell peppers, or virtually anything that isn't going to burn up (like cheese will). Wrap tightly and throw on a medium hot grill. These packets will cook up in about 20 to 30 minutes. Check to make sure they are done before you pull them off the grill and be careful opening the packets because the steam inside can be around 500 degrees F (260 degrees C.).
Straight off the Grill: You can grill potato slices or wedges quickly and easily on the grill if you are willing to keep a close eye on them. Your best bet is to cut the potatoes into long thin wedges. This will let them cook faster. You can peel them or leave the skins on. Once you have the potatoes chopped up toss them with a good oil and seasoning mixture. Italian dressing works great for this. Place them straight on the grill or in a grill basket over a medium heat and cook until they get soft. This will take about 20 minutes. You can baste them while they cook. You will need to flip your potato wedges periodically to prevent burning.
Short Cut Potatoes; The fastest way to grill your potatoes is to parboil them first. This is done by taken your sliced potatoes and throwing them in boiling water for about 10 minutes. Drain and place on a medium hot grill and they will be cooked in another 5 to 10 minutes. When you take the potatoes out of the hot water it is best to drain them well and then coat with whatever seasonings sound good to you.