Re: Please Fix Your Signatures!
If I remember correctly you can limit the signature/avatar size in PHP from the User Control Panel. Try finding a plug-in that automatically does this when someone attempts to upload an image outside of the range you are requesting. Worse case, warn everyone of the impending doom, remove all signatures, then set the standard so everyone can readjust and upload the appropriate size.
Removing sigs entirely, is a no no. It is one small way people get to express themselves and stand out in a rather large community. I may not remember what you said but I sure bet I remember that picture with the crazy guy smoking a hookah, or some such nonsense.