I thought people used to use oatmeal in a bath tub. If I remmeber correctly, they grind it up fairly fine in a blender, then throw it in the warm wate (not too hot) and try soaking in that. Keep the water on the coolish side.
The afterburn aloe lotion. Absolutely something I swear by since I burn quite often :/ and its really soothing. You can pick it up in a cvs or rite aid or any pharmacy store like that in the lotion section
I agree w kait18...but just straight aloe gel is cheaper and as effective. If you are going to use vinegar it is best to use it directly after the exposure - or asap after, anyway. Sprinkle it on a flour sack type tea towel and put it on your skin. It stinks, but it does help.
Hopefully by now your sunburn is starting to go away. But for future mishaps, drink TONS of water and I mean TONS. I literally have a gallon with me as soon as I know I got burnt. Your skin will be trying to heal itself and will be dehydrated so water will replenish it. Gatorade or green tea are not bad ideas either. Aloe makes it feel better but I think it dries it out more from the alcohol they put in the gel. I like Aveeno daily moisturizer for burnt skin. It doesn't feel as nice at first...actually it feels kinda gross on sunburn but it does keep it moisturized (i.e. Faster healing). If you can, don't put clothes on the burnt areas, put ice packs (wrapped in a soft towel) on the areas, and sit in front of a fan.