I bought my PS3 just last December, first one i ever got (ya I waited awhile lol) .... got the 320 gig Infamous 2 bundle. Havent' had a single problem with it (except for Bugrim... errr Skyrim... freezing on me and crap. But at least I was able to finish the game unlike some people.... too bad Bethesda's too **bleep** stupid to get DLC to work like EVERYONE else in the industry apparently can with no problems), but even with the Slim I've noticed online on various sites alot of people posting about the YLOD and other failures even with the Slim. You'd think they'd have older FATS that liked to overheat, but no some had newer slims. So...... below I'm pasting something I typed in another thread. If the YLOD is from the slim overheating, doing what I did beow should keep that from happening.
when I got my slim (infamous 2 bundle) last Dec..... even though Sony had made the slim to solve the overheating problem (more airflow inside with lesss hardware taking up space like hubs for 4 usb ports and the card reader and other things) not to mention cut costs, i noticed mine got hot as hell. Not the whole thing, but the back half of the cover over the "exhaust" in the back. Since then I got one of these: http://www.amazon.com/gp/product/B002MU1ZRS/ref=oh_details_o05_s00_i00
With a laptop cooler like that, the bottom of the PS3 itself is blocking the air coming from the middle of the cooler, forcing the air from the cooler to the sides through the mesh in the top of it (the mesh top of the cooler that is)...... RIGHT into the little slits ALL around the bottom edges of the PS3. Since I got that cooler, my PS3 barely even gets lukewarm leaving it on for days at a time sometimes. So...... even if you have a slim that shouldn't overheat.... i suggest everyone uses a laptop cooler on it, especially the one I linked. If you haven't thought of using a laptop cooler, you should. But if you dont' get the one I linked, you at least need one with fans that are in the right spot (directly under the slits on the bottom on the system).
I take mine apart about once a year and just blow canned air through it. I have a 250 GB slim (the original slim, not the new sliding top one) and mine rarely gets above warm with the stock cooler though. It's got an insane heatsink in there though and a monstrous fan that will keep spinning on its own for like 10 seconds after I stop with the canned air, so at least with my model, they apparently had a very efficient cooling system, and it's not loud either. My PS3 stays on for 8+ hours a day and has just about every day for the past 3 1/2 years, whether I'm playing a game or my wife and kid are watching Hulu/Netflix.
The only bad thing about it is that by opening your console, even just to clean it out, you void your warranty. One of the screws you have to take out is covered by a warranty sticker that will get bubbles in it if you peel it back to disassemble your console. If you want to try cleaning your console yourself there are plenty of videos on YouTube about it. For the first 2 years I just took canned air and sprayed into the back ventilation holes and up through the side slits, but when I got brave and opened it for the first time it was still pretty funky actually "inside" the console. Surprisingly, the PS3 is not complicated to take apart, as long as you don't start trying to take out the boards. You can totally remove the blueray drive and the power supply in about 5 minutes, and most of that is taking out the screws in the bottom of the console. When I take mine apart to clean it the only things I take out is the disc drive and the power supply. The rest of it is pretty open and I just point canned air down in between the fan blades and blow dust out of the heatsink.
I may invest in one of those laptop coolers anyway just to sit mine on, preferably one with its own power cord because between my Playstation surround sound headphones and either my phone or controller charger, both of the USB ports are always in use.
This is why I stand by having a PS3 sit vertical and not horizontal.
Both my launch day 60Gb and 80Gb have always sat vertial since purchase and they are still going strong.
I also keep my house temp between 68-72*F.
I had a friend stay with me from Thanksgiving until the new year currently and his Slim PS3 is barely heating up. He also stands his PS3 up.
Yes the Bottom does get a bit warm, either elevating it using bottle caps, or standing it vertical, or like you, use a laptop cooler.
Changing the thermal paste on heat sinks & CPU/GPU to high quality one is IMO the most effective way of prolonging your PS3's lifespan. Also cleaning the dust out once a year or so helps a lot to. There are a few other things you can do to the fat ps3's such as replace the 15 blade fan with a 19 blade one & replacing the power supply with a more efficient one but I do not think that either of those tips apply to the slim models. There are many videos & guides available on the net detailing how to disassemble & change the thermal paste in all the different model PS3s. So as long as you have some experience with fixing electronics it is very easy to do. I recommend using MX-4 or Artic Silver 5 as the replacement thermal paste.