I change the 4runner every 3-5k with Mobil 1 full syn, and the Rav4 every 5k with the same. Filter changes everytime.
Always really dirty when it comes out, so I figure its time. The rav gets expensive since it sees 40-45k per year.
The 4runner gets it just for fun. I like the idea of really clean oil in there. I also change the air filter regularly, and the diffs and trans/tcase once a year. Spark plugs, and coolant every 30k.
Am I wasting money? Probably. Then again, its a high mileage motor and I beat on it alot (The SC gets really fun at 5 grand
I take the oil to the Oreilly's on 88th and Wads since it is across the street, and the rest of the stuff to the Rooney Road recycling center, which is free for some stuff, costs for others (I think paint and brake fluid cost, and anti-freeze is free, but I can't remember).
As for that Oreilly's being full all the time, I think it depends on who you talk to. Seriously. There are a couple of guys there I think are toking the bong a bit too much while at work.