ShapeCatcher.com helps you to find the right Unicode characters. All you have to do is draw the Unicode character you're looking for, and the site will show you the closest matches in their database. Currently, there are 10877 Unicode character glyphs in their database.
Note: The site currently doesn't support Japanese, Korean and Chinese characters.
If you don't know what Unicode is, per Wikipedia it's "a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems. " (read the rest of the article)