Curses can be rather fun... well, not if you are on the receiving end. But in terms of interesting events, a curse can be a powerful plot driver, although hitherto, game mechanics have not supported curses well despite their role-playing potential.
Here is an attempt to redress this, by making curses more interesting mechanically. Basically, curses are treated as intelligent entities capable of employing various powers each day against the luckless soul who is cursed. Each curse has a set of 'moral axioms', a code of behaviour which it wishes to impose on the victim and it uses its powers to modify the victim's behaviour by a mechanism whereby it is granted extra ones if the victim does not conform! The fun bit is that the character afflicted may have no idea, at least at first, what moral axioms the curse has.
To throw off a curse, the victim may seek magical help or attempt more exotic methods such as following the curse's moral axioms to such an extent that it no longer has effect. Also, each curse designed using this system will have a method for removal included - again, not something the victim will be privy to.
Five mythic curses are provided as examples, which may be used as presented or as a basis for your own designs. These curses - Ageing, Babble, Gender Reversal, Ill Fortune and Petrification - do not come with their own moral axioms, however a list of suitable ones is provided so you may add whichever you feel are appropriate. These can involve things like controlling fear or your temper, displaying generousity or even avoiding drunkenness. Interestingly, the moral axioms presented are all good things. It's entirely likely that a curse bestowed by an evil creature may have a more malign influence!
Finally, if you decide to let characters bestow curses as well as suffer them, there is a Mythic Curse feat that the would-be curser can take.
Altogether interesting, and certainly making curses more exciting.