where can I find a foldable mattress for a fold up cot?
I just found a old sturdy foldable roll out bed at a garage sale, but the mattress is smelly, I like the thickness and the ticking stripe on it, does anyone know where I can find one thats similar to that mattress? or is there any way to clean it?

You could leave it out in the sun for a few days to completely air out. I would be concerned with dampness all the way through the mattress, however. I would think that you would then have mold.
You could also try and spray it with Febreeze. It does do amazing things for odors.
JC Penney
http://www4.jcpenney.com/jcp/ProductsHOM.aspx?RefPage=PRODUCTLIST&DeptID=25436&PCatID=28950&CatID=30743&CatTyp=DEP&Dep=Bed+&PCat=pillows+%2b+pads&Cat=foam+toppers&GrpTyp=ENS&ItemTyp=G&ItemID=1126e19&Page=1&ProdCount=10&ProdSeq=5&Sale=&mscssid=62ff0d46237594f098138199ff004ab16xMnVNoVza3oxMnVNoVza3W200B1EF581C36D5723BE57BD4BC842F096270713318&CmCatId=EXTERNAL|30743&Bedsize=T
FoamByMail
http://www.foambymail.com/mattresses.html