I'm currently using AES encryption (at home) on GNU/Linux (one of LUKS AES-256 variants with xts) and on Windows 7 (Truecrypt) with a 15 characters password (alfanumeric undercase only plus _).

Should this be enough or would it be better to change towards a longer password. How long should it be  ? Recently viewing the results with GPU cracking I got a little worried. The thing is that I wouldn't really choose a password too long so tha I'd not forget it and get locked out myself.

I'm currently using AES encryption (at home) on GNU/Linux (one of LUKS AES-256 variants with xts) and on Windows 7 (Truecrypt) with a 15 characters password (alphanumeric lowercase only plus _).

Should this be enough or would it be better to change towards a longer password. How long should it be? Recently viewing the results with GPU cracking I got a little worried. The thing is that I don't want to choose a password so long so that I'd forget it and get locked out.