If you mean as a learning experience, then yes, that can be a good way to get some practice. Keep in mind however that to do it properly you shouldn't just be going through line-by-line looking for equivalent statements in the language you're changing to, but rather should be rewriting things to fit in with the idiomatic use of the languages in question - so the requirements for each program will be the same, but the method of solving the problem in each language, and well as how your chosen solutions are expressed will probably be quite different.

You could of course simply solve new problems in each language instead, or perhaps try your hand at some Project Euler questions. If you think you might benefit by all means try reworking some programs in a different language though - if nothing else, it can be quite interesting to see how different the solutions can sometimes be.