Tools:
PDB Viewer
Released 20-Jul-2010, Plugins for ollydbg and IDA to show lots of PDB info
IDA ManageMarks
Updated 24-Sep-2006, ManageMarks is an IDA plugin to provide functionality for IDA markers.
Incubator
Released 27-Sep-2006
Incubator makes developing shellcode easier.
LibPePatch
Released 10-Oct-2006
LibPePatch makes modifying binaries easier.