Reader Captain Duck spotted a possible fix in the Something Awful forums: Disable your access to the Playstation Network. SA Goons (an accredited rank in GTA: Vice City) surmise that the game is looking for multiplayer connections "every two minutes or so," and if something is wrong there, voila, lockups.
Kotaku doesn't vouch for the efficacy of this measure on all consoles but the SA commenters sure do:
"THIS TOTALLY Works."
"Yep, until they patch it, disabling internet access on the PS3 seems to do the job. It has worked fine for me, helped with a lot of the frustration I was having. Thanks guys"
Looking at the date stamps to the comments, I realise this is about three days late, and I hope I'm not advertising something everyone already knows as breaking news. If you guys already figured this out in the comments, good on ya.
But ... in the interest of useful info, there you go. Also, if anyone has different freeze problems or solutions, hit up the comments.
Freezes - in two flavours, "intro scene" berry and "random" bananarama [Something Awful forums]
Note: You'll need a full acount to see more than the first page.
Update: Thanks to commenter zimzombie for the swell borked image redo. He's right, Chef totally needs a gun.