I'm using "Parameterized Build"
(http://wiki.jenkins-ci.org/display/JENKINS/Parameterized+Build) and hudson
eclipse plugin (http://code.google.com/p/hudson-eclipse/). It would be good to
get the list of declared parameters and default values from hudson
(http://code.google.com/p/hudson-eclipse/issues/detail?id=31#c1).

With URL "http://server/job/myjob/buildParameters" hudson should return simple
page with parameters and assigned values:
...
Param1=value1
Param2=
Param3=value3
...

This page can be parsed with a script or eclipse plugin. So it is possible to
schedule build with default parameters or changed parameters by user:
http://server/job/myjob/buildWithParameters?Param1=value1?Param2=user_value2?Param3=user_value3

If the build is not parametrized, hudson should return an empty page and normal
build can be started:
http://server/job/myjob/build

Andre