File conversion

[Comixion]

Where can I find a good free file converter or something online.
I have a .plt file that needs to be converted to a .jpg.

[dog2525]

see if this will work
http://www.zamzar.com/

[Comixion]

Well, thats a pretty good non-downloadable program and I'll use it again for other files but it does not recognize my .plt (plotter) files for some reason. They are files used for vinyl plotter machines.
Sometimes, like now, I need to convert these files to .jpg or .bmp in order to print them and/or work with them when using other imaging software. I once used one called Irfanview but its not functioning.