Version 2.8 of PFDAVAdmin can be downloaded here:

http://www.microsoft.com/downloads/details.aspx?familyid=635be792-d8ad-49e3-ada4-e2422c0ab424&displaylang=en

It seems to need .NET 1.1 to access the Exchange mailboxes and public folders.  This is best done on an admin machine (not the Exchange server as installing v1.1 might break v2.0 and Exchange itself!).)

Download 1.1 and SP1 here:

http://www.microsoft.com/Downloads/details.aspx?FamilyId=262D25E3-F589-4842-8157-034D1E7CF3A3&displaylang=en
http://www.microsoft.com/Downloads/details.aspx?familyid=A8F5654F-088E-40B2-BBDB-A83353618B38&displaylang=en

Installing .NET on Vista x64 gives a compatibility error (with IIS), although installs okay.  See http://www.mydigitallife.info/2007/12/27/install-microsoft-net-framework-11-on-windows-vista-fix-regsvcsexe-fails-error/ for related (?) details.