TripPlanners

list of OSM routing engines

http://wiki.openstreetmap.org/wiki/Routing/online_routers

OSM Folks Planner (slick / worldwide, but not OSS)

http://maps.cloudmade.com - Bike/Walk/Car

**OSS routing for OSM data - Bike/Walk/Car **

http://www.yournavigation.org/

http://wiki.openstreetmap.org/wiki/YOURS

http://www.yournavigation.org/about.html

http://svn.openstreetmap.org/applications/routing/ Code for Yours (and also something called PyRouting)

Bike routing for England, with detailed results and cool map snapshots - OSM data (Not OSS yet, but they plan to make it so)

http://www.cyclestreets.net/journey/113879/

http://www.cyclestreets.net/blog/2010/03/10/lessons-from-the-developer-day/

http://OpenCycleMap.org

OSS multi-modal planner (Germany only)

http://szipf03.geog.uni-heidelberg.de/openrouteservice/

http://szipf03.geog.uni-heidelberg.de/openrouteservice/contact.php

http://openrouteservice.org/

Misc

http://opengeodata.org/osm-routing

http://wiki.openstreetmap.org/wiki/Gosmore

http://blog.gmane.org/gmane.comp.gis.openstreetmap.routing (contains many different trip planners based on OSM data)