Funimation recently announced their plans to re-release season one of Sgt. Frog as a single box set. This box set will include 26 episodes, whereas the original releases of season one, part one and season one part two included 13 episodes a piece. MSRP for the new season one box set is $49.98, though Amazon currently has it priced at $36.99. The box set will be released on February 15, 2011.
Trailer for the re-release (if you've seen the trailer for the original releases, it's the same trailer):