All of the 'plug/play' LED bulbs out there are garbage. They will not light up the lens housing enough especially in the day time. You can go over to HIDPlanet and do a search on them there. Most have been reviewed there, and the outcome is always the same. Especially in the day time, you can almost not see them. Also many don't seem to last very long, I think they overdrive the LEDs to get more brightness out of them, and they die prematurely.
I'm the one that the previous poster mentioned that used truck modules in my 04. They turned out fine, but it wasn't an easy mod. I did mine before the 06's came out, if I would have known that they were going to have LED from the factory. I would have just purchased those...
I also converted my bumper lights to LED too, used superflux LEDs and perf board from radio shack. They light up the housing just as bright as the tail lights too, and have been going strong for about 5 years now!
http://www.toyota-4runner.org/audio-electronics/12315-led-tail-lights-installed.html
http://www.toyota-4runner.org/accessories/15651-my-led-bumper-light-conversion.html