Special characters don't add as much to security as you might think. They increase the number of possible characters, but the most powerful multiplier comes from password length.
Let's say you have a very limited character set consisting of [A-Z][a-z][0-9], giving you 62 possible characters. Therefore a 10 character password has 62^10 possible passwords, or 8.3*10^17. Now add 10 special characters, and the number of possibilities goes to 72^10 possible passwords, or 3.2*10^18.
Choosing an 11 character password from the simple set, you have 62^11 possible passwords, or 5.2*10^19, which is another order of magnitude stronger than adding symbols to a 10 character password.
Of course, if you're picking only dictionary words, even with symbol substitutions, John the Ripper will likely shred the password in short order. Pick long passwords that aren't dictionary words, and you'll make a real difference in your security.