I'm thinking of installing a Linux distro onto a BlackBerry, as a BB uses ARM architecture I'm guessing that Raspbian should work fine on it? Does anyone have any experience with this sort of procedure, I would like confirmation that this works before I brick my phone.

I'm going to try it out on an old BlackBerry Curve and report back with the results.

I'm going to have a look around, I think Robby had the same idea as me a while back.

It's not possible. Trust me - I have three old blackberry phones laying around that I had hoped to get an alternate OS onto, and I searched high and low to no avail. If the BB had the market share that the iPhone has, perhaps someone, somewhere, would've cracked the bootloader on at least one model, but alas, they're a niche device mostly owned by businessmen, and there's virtually no community of hackers focused on the blackberry.