If you've ever owned a first generation X-box 360, then the chances are good that you've sealed the little guy in his styrofoam coffin, uttered a prayer, and sent him away for resurrection at least once.
I partook in this ritual myself, when my 360 went on strike and refused to play the games I purchased for it; not unlike a spoiled 10 year old. Overall it was a fairly painless process. Microsoft was helpful, and turnaround time was about a week. Still, it's not something I look forward to doing on a quarterly basis.
Looking for anything that could prolong my console's lifespan, I finally settled on the Nyko Intercooler TS. It's basically another unit consisting of 3 fans, designed to expel heat from the back of your 360. As any X-box owner will tell you, the console generates slightly less heat than a blast furnace, so anything that helps it run cooler can only be a good thing.
The unit itself is fairly small, clips firmly to the back of your 360 and doesn't obscure any of it's outputs. It even has it's own AC adapter, unlike the old intercooler models which relied on the 360's power cord and had a tendency to short circuit consoles, in a hilariously ironic twist. It also has a temperature sensor, which (in theory) only turns the fans on when the console gets hot. In reality it's just on the whole time, and stays on for a while after the 360 shuts down. What does that say about it's heat output?
So now the million dollar question is: Does it actually work? And the answer to that is a resounding "I guess so". It's a hard thing to prove, as there are many other factors at play here. But I've been using mine for over a year and my 360 has yet to unceremoniously shit the bed again. If you put your hand behind the console, the exhaust no longer feels scalding but simply warm. So it definitely does keep things a bit cooler.
So everything is great, right? Well not exactly. The one big caveat is the noise. The old 360s were not quiet to begin with, and the intercooler increases it's noise output level from "Harrier lifting off" to "Flock of geese passing through a jet turbine". It's pretty loud, but like renting an apartment underneath a main subway line, you get used to the noise after a while. Only when you have company over will they take note of it as you shout at each other over the din.
Over all the Nyko Intercooler is a good product that does what it is supposed to, which is keeping your 360 from erupting into flames. If you can tolerate the cacophony then it's cheap insurance against the dreaded RROD.