Originally Posted by
spivonious
I replaced my chain once and found that the sprockets had worn out too. This caused the new chain to skip horribly for a few weeks. Now it's worn to match the sprockets and I'm sure doesn't meet any chain stretch measurements. But you know what? The bike rides fine. If the chain breaks on my way to work, then I'll walk the rest of the way and buy a new chain and cassette.
Somewhere along the line I picked up one of these:
It's pretty compact. If you also take along a couple of extra links you can save yourself some walking (though you might get by without those).