Found this page from a link given by someone at Ask.FT.
REMOVE CHEWING GUM
Chewing gum is not my favorite type of candy or sweet thing but the kids sure love it. If you ever look down at a pavement you can see where people have spat out their chewing gum for you to step in. It is a terrible problem for local authorities who are in charge of cleaning it up, as soon as they remove it, someone will replace it.
I have gathered a multitude of ways that you can remove chewing gum from your hair, clothes and carpets. So read on if you are looking to remove some chewing gum.
The white of an egg will remove chewing gum from most things, including your hair. Put the white of an egg on the gum and leave for a couple of minutes. Then work the gum out with your fingers little by little.
Freeze it out.
If the chewing gum is on an item of clothing, put the item in the freezer. The chewing gum will go hard and all you need to do is crack it off. You can also use the freezing technique on larger items, such as a car seat or carpet, by using ice cubes. Place an ice cube onto the gum and slowly rub it around. The gum will harden and you will be able to crack it off in big pieces.
This technique will work great if you have chewing gum in your clothes or hair. Melt some chocolate and rub some of the melted chocolate into the gum. The chocolate dissolves the chewing gum's stickiness - so it can be brushed or combed out instead of having to cut it out.
Mayonnaise will also remove chewing gum. Simply apply and work it in, gum softens and comes off easily.
Saturate the area that has the gum on it with vinegar. The gum will actually dissolve. If the vinegar is heated first the process will work faster.
Simply apply peanut butter to the offending gum and work it in. The gum comes right off.
Chewing gum can be removed from clothes if the gum is first soaked in lemon juice and then the clothes are washed as normal.
Very similar to the other tips. Simply spray the sticky gum with WD40 and work it into the gum. The gum will come out easily.
[Taken from this page.]