Actually, though nowhere near as flexible and full-featured as Lars' proposal, we already have the beginnings of a list builder in the OpenACS.
Just use the templating system to create a "grid"-style form, generate "inform" widgets, then set "has_submit" to 1 so that you don't get any submit button. Something like:
template::form create list -has_submit 1
template::element create list foo -widget inform -value hello
template::element create list bar -widget inform -value there
set headers {Foo Bar}
set title {A List}
then in your *.adp:
<formtemplate id=list style=grid cols=2 headers=@headers@ title=@title@></formtemplate>
This would actually work and might give some ideas for a list/table builder.
