Do any companies still do a 4-week notice period or is it standard to just be paid out and escorted off-site right away? I've seen both big and small businesses go for the quick route of canning someone on the spot. It's never affected me personally but I can't imagine anything worse for the unfortunate people who it happens to.
Recently saw a guy get made redundant after 10 years at the company. He didn't even get a chance to say goodbye to his colleagues/clients, wrap up his work, or take it in. Just told to pack up his stuff and wait for his money. Meanwhile people who started just a few weeks prior and decided the job wasn't for them (effectively wasting the company's time) get the typical farewell parade, goodbye lunch, sob story about how much we'll miss you and what an asset you've been. It just seems like a patronising cultural gesture.
Moral of the story - don't get made redundant, I guess.