Multiple Values For RestrictToCategory or Better Ideas

Hello,I am working on a RSS Aggregator that will end up being a customizable portlet… My idea is to create documents with what each user wants to subscripe to and then show a web view with just the feeds shown that they subscribed to… My original plan was to create a form with an embedded view that the address would pas the user id via Query string and then their would be a field on the form that would do a dblookup using the QSparameter and then bring back all the items subscribed to and then pass them it to the embedded (restrcited to category) view… My question is can you pass multiple values using restrict to category so you have multiple categories shown or is there a better way to do it? I’d prefer to use the fastest ways to do this (no agents if at all possible) due to alot of people will use this and it needs to be fast… Thanks!