Yes there are a lot of free picture hosting places around the web, however it all depends on how many pictures you are dealing with because they usually only give you enough space/bandwidth for a few pics. some camera companies offer free picture hosting via their software that may come with the purchase of the camera
here is one you may want to try
HereIf you have never done this type of thing before it is quite simple, once you have a host you upload the images to their server in turn they will grant you an url for each pic. you then copy the url and click on the img tag found along the top of the message box. you will be prompted to enter the url.
if an image resizer is needed you can find one
HereI would like to mention that some forum based message boards do not allow free hosting from such places as Geocities, Yahoo, ect. ect. I have not used their services!
hope this helps ya out