These rolling cases from SKB are excellent for gear that you have to handle a lot. The luggage-style handle and wheels dramatically reduce the amount of lifting and the rounded plastic corners are easy on your back seat. 4U units are available as well as "Shock Rack" cases.

This is a good old-school multi-purpose foot controller for rigs that use MIDI controllable hardware like the G2. The dual pedals one-up the MPX R1 by Lexicon which also has noisy buttons compared to the Behringer. No USB but otherwise an excellent pedal for a low price.

If you're using a rack, have a lot of MIDI gear and need to interface with computer an 8 x 8 (8 in, 8 out) MIDI interface like the MOTU MIDI Express 128 is worth looking at. Most of the connectors are on the back but one MIDI IN and one MIDI OUT is available from the front panel which is good for a footpedal or keyboard that you might be plugging and unplugging a lot. Both Apple OS X and Windows drivers are available. The Users Guide provides a good overview of using MIDI in your rig (more on MOTO's Manual page).

If you're carrying around a rack, you might consider picking up one of these solid state rack mount recorders from Tascam. They are really for the broadcast and sound re-enforcement markets but are a lot more beefy than a laptop if you use backing tracks or want to record shows. The SS-CDR200 has balanced and unbalanced analog IO, coaxial S/PDIF or AES/EBU digital Io, records wav and mp3 files and even burns CDs.