Axis 2100, 210 series net cameras (and quite possibly most Axis models) 
.. work very well with motion. Use this link in your motion.conf:
 
-  Axis 210: netcam_url http://CAMERA_IP/axis-cgi/jpg/image.cgi?resolution=640x480
  -  Axis 2100 single jpg: netcam_url http://CAMERA_IP/axis-cgi/jpg/image.cgi?showlength=1
  -  Axis 2100 mjpeg stream: netcam_url http://CAMERA_IP/axis-cgi/mjpg/video.cgi?showlength=1
 
 
For the Axis 2100 replace 
resolution=640x480 with its max. resolution of 
320x240
-- 
RupertRoeslerSchmidt - 25 Oct 2004
  Axis 206, 241 
Camera at 
CAMERA_IP/view/index.shtml
Use 
CAMERA_IP/mjpeg/X/image.mjpg, where 'X' is the camera number, e.g. '1'
  Axis 206W (and quite possibly most Axis models) 
.. work very well with motion. Use this link in your motion.conf:
 
-  Axis 206W: 
netcam_url http://CAMERA_IP/axis-cgi/jpg/image.cgi?resolution=640x480
 
 
Thanks 
RupertRoeslerSchmidt.
-- 
EricBEAUFILS - 09 Nov 2006
  Axis 241Q 
If you want to put username and password in your link:
netcam_url http://username:password@AXIS_Server_IP/axis-cgi/mjpg/video.cgi?resolution=2CIF&camera=X (X is the camera, e.g Video1,2,3 or 4)
or
netcam_url http://username:password@AXIS_Server_IP/axis-cgi/jpg/image.cgi?resolution=4CIF&camera=X
Without username and password:
netcam_url http://AXIS_Server_IP/axis-cgi/mjpg/video.cgi?resolution=2CIF&camera=X (X is the camera, e.g Video1,2,3 or 4)
or
netcam_url http://AXIS_Server_IP/axis-cgi/jpg/image.cgi?resolution=4CIF&camera=X
Good luck
  Axis M1011-W 
Worked without problems.
Used:
http://path_to_cam/mjpg/video.mjpg
http:// path_to_cam / jpg / 1 / image.jpg
Works very well in darkness (tough the image becomes b&w)!
-- 
JorgenVanDerVelde - 10 Jan 2012
  Axis M3005-V 
Worked without problems. Make sure when using 
WebService: Enabled in the camera setup, you must have synced ntp time on the computer running motion and the Axis camera.
Used: "http://USER:PASS@X.X.X.X:PORT/axis-cgi/mjpg/video.cgi?user=USER&pwd=PASS&resolution=640x480" for netcam_url in thread.conf.
Only daylight support