Ask HN: What are the useful parts of agile programming?

It seems like the useful parts are:

1) Build and deploy the smallest useful part first. > Get's the project moving and not canceled.

2) Break request into separate time lines. > Give management choices vs. death marches.

3) When two coders are talking about a problem sit down together at a desktop and fix the code. > Avoid wasting time talking about stuff you don't really understand.

Anything else?