Having had to reset a PS3 twice and now with a replacement one, so a third time of setting one up this month.. I have spent no small amount of time trying to find iPlayer.
The internety is AWASH with how to find it. From "it'll just pop up one day" to "go to the iplayer website"... all wrong. It's also NOT downloadable from the Sony shop thingy on the PS3.
It IS installed with PLAYSTATION HOME.
ie.... even if you don't want to play in a virtual online world...
Go to PLAYSTATION HOME on your Sony CrossMediaBar (XMB), and agree to install PLAYSTATION HOME.
IF it fails to load once it's downloaded, (I got a purple screen.. total PS3 lock up.. re boot PS3).. use the green button on your controller on PLAYSTATION HOME and choose un-install and then choose to install it again (I had to do that twice)
Once it's installed, you'll find iPlayer back in the normal section of the XMB where it should be.
You can thank me now