Using Hudson to build different branches of a project it would be great to be
able to share the incrementing counter of the builds.

One way would be to add a reference to the "master"-job (HEAD-build) to share
its incrementation counter. Probably there are some problems if such referenced
jobs starting their tasks in parallel?

Another solution would be to define global counters and the jobs can refer to
this global counters.

I could imagine, that someone would like to add also some pre- or postfixes to
the numbers to identify the artifacts. This could be on one hand the job-name,
but on the other hand also an additional number.

Example:
Head-Build: 0.389 -> 0: it is head, 389: number of build
Branch1-Build: 1.388 -> 0: is Branch1, 388: number of build

But this pre-/postfixing could also be managed by the configuration of the
build-scripts and is better placed there.