I was in urgent need of product specific coupons functionality, which doesn't seem to be present in virtuemart. Therefore, building on the fact that an unpublished product category shows up if you build the url manually, I've written this little coupon redirector. All it does is, accepts the names of 4 coupons and 4 redirection URLs (1 for each). When the customer enters the name of a coupon, it redirects to the URL, which is the URL for an unpublished virtuemart category, containing reduced price products. Easy and simple to use, it is quite lightweight. Let me know if you need help with anything in it. Please note that the coupons you use here do not have to be virtuemart coupons. You also do not need virtuemart to use this module.
Updated 08 Jan 2007 [0.3]: Added the ‘module class suffix’ parameter. Thanks to Jos van der Voort for the suggestion.