I'm working on-site with a client now in Clearwater for a several month
engagement where I'm a full-time ScrumMaster for a few projects (large
and small) - I'm curious to hear - what kinds of tools (digital, paper,
whatever) are people on this list using to track product backlogs,
sprint backlogs, and burndowns?

At the client here, we are using MS Team Foundation Server with the
Conchango process template (http://www.scrumforteamsystem.com) to track
product backlog items, sprint backlog items, impediements, bugs and
retrospective discussions (and get all the burndown reporting that
comes with that).

Anything else being used locally of interest?

-- Ryan