Catalina Express costs about $33 per person round trip. You can ferry across boats, bikes, kayaks and such. I've never done it though... so I don't have much information about that. Last time I went, I paid ~$230 for a room for two nights, 2 catalina express tickets, and 2 "tours" (i.e. one for each person). This was towards the end of September and off-season prices, though. I stayed at a place called La Paloma. Not the glitziest place, but I didn't go to stay in the room anyway.
Catalina Express leaves from Long Beach, Newport, and Dana Point at about.... um... every hour or so (~9am-7pm). The trip takes about 45 minutes.