This is an generic, flexible foraging system that is backwards compatible with wyrin's foraging system (http://nwvault.ign.com/View.php?view=NWN2Scripts.Detail&id=225). It uses the same script name, so it can be retrofit to any module that uses his system with no additional work, or used as an override by a player. I haven't tested PW use, as I don't develop for one.

Differences:
Allows customization of rewards (stack size supported), skills to check, skill dc, animations/sounds/messages to play. These are stored as local variables on the placeable. Partial success is allowed, with separate rewards and player messages. Skill checks are party-wide, not just the user of the placeable (not fully tested that bit yet).

Usage: In addition to the normal foraging of plants, you could "forage" a painting by checking appraise and or lore, discover a sword is heirloom quality with craft weapon, make the pc dance a jig on success, etc.

Support for wyrin's system:
Wyrin's system includes placeables, and these are treated as a special case, checked for by their tag. Wyrin's items all start their tag "forage_", so that's what's checked for (so don't tag your new forage-able placeable that way). Script includes both wyrin's original skill checks (item user's skills only), and party-wide skills checked, so you can pick what you prefer.

10/28/2012: updated, the script no longer repeats skill checks, you could previously succeed on a single check for complete success, but fail both checks for partial success, confusing the player. Script now lists the skills and the integers in the comments, clarifying that it uses the game's default global values for these.