The DTE RS-232 module is a tight and tidy way to convert RS-232 (computer-level) signals down to a microcontroller level signal strengths. DCE means it's configured as a "Data Communications Equipment" (with 9 holes).
The Solarbotics Arduino Freeduino Enclosure (SAFE) is a laser-cut acrylic case for your Arduino Mega. It also has the added feature that it can house an Arduino or Freeduino instead with a MEGA amount of space left inside.
The iMax B6 Balance Charger accurately balances and charges Lithium Polymer, LiFe (A123), NiCd and NiMH batteries. The B6 will balance charge LiPo/LiFe up to 6S and NiMH/NiCd up to 15S and shows individual cell voltage during charge with realtime updates throughout the charge cycle.