Are there any remedies for a bee sting?

The most important thing when a bee stings is to get the sting out as quickly as possible because it can continue injecting venom for up to a minute. The best way is to scrape it out with a thumbnail or something like the back of a knife or the edge of a credit card.
There is little you can do to neutralize the venom because it has been injected under the surface of the skin. Any chemicals on the surface strong enough to reach the venom would probably damage the skin.
The best thing to do is treat any symptoms: a cold compress will help reduce swelling (use something like a bag of frozen peas if you can't find anything else); calomine lotion will help reduce itching if there is any.
If the person has been stung many times or feels faint or starts to have problems with breathing, get medical help.

Ice and toothpaste seem to be popular home remedies to ease the initial pain of bee stings. Do not squeeze the area stung, this will cause greater pain to the site.