The most commonly used hashers are pwdhash, supergenpass and magicpassword. Given that they all use hashing algorithms, none of them will result in a password using special characters, which is not optimal.
Actually, that's not true. Look at the encoding section of the PwdHash USENIX paper. PwdHash returns an ASCII representation (not a hex or base64 encoded string) of the hashed domain name + master password. PwdHash also applies a number of constraints to the returned hash to ensure that the special characters that it does use are legal at most websites.
A typical PwdHash password, with domain name google.com and master password "LetMeIn+123456?" looks like this:
Optimal? No. More than sufficient? Yes. You can use all numbers in your password, so long as it's long enough (and the website actually uses all of them).
I use a hashing bookmarklet myself. Only, I wish there was a better algorithm and I think it's wise, at least with an audience like HN, to point the weaknesses of those system. See for instance : http://stackoverflow.com/questions/554224/is-the-bookmarklet...
