I'm kind of ambivalent about the s prefix for strings. I know I've used it in places. I think the value in hungarian notation largely comes in knowing the numeric type (i/f/d) and whether it's a pointer or not (p). I think the value kind of diminishes after that. For complex classes I feel fine w/ no hungarian notation.

I also kind of intentionally mentioned Hungarian notation as optional in the coding guidelines:
http://mixxx.org/wiki/doku.php/coding_guidelines#variables