Btw, I've wondered this for a while. Back in 2.0 days, there was a small repository of applyable patches (iBCS2, PC speaker sound card emulation, dual monitor support and Co.), which weren't included in the mainline kernel. The externel hosting was never an official feature, though.
But what about today? Where do patches go if they are rejected? Is everything just thrown away?? Shouldn't there be a public review and archival repository somewhere? Or even a separate GIT for incoming patches? (Can't believe it's all sent per email.)
If use contributed patches don't make it INTO the kernel, it would help if they were at least AVAILABLE somewhere. Otherwise there is little chance for user lobbying, or at least patching your own kernel.