Peter suggests that everyone using SHA-1 should move to SHA-256. That's a reasonable suggestion, but I say as long as you're making hashing changes why not move to SHA-512.
Remember, it's also in the FIPS SHA-2 standard and faster on 64bit CPUs then SHA-256. It's only 64 bytes long, surly that's not too much to handle.
Edit: Goggle also suggests SHA-256, so perhaps Peter was simply seconding the recommendation. I suggest SHA-512 is the better recommendation.
Instead of just migrating everything to a new hashing function when something gets bad, why not migrate to something that would be future-proof and easy to switch out? Multihash[0] is one solution, where a hash contains information about what hash-function was used when generating the hash, so you can have the same input, multiple hashes.