I use my laptop with a lacie sata II expresscard 34 in the express card slot and a Addonics AEPDDESU card reader with an sata port, I have 64 gig cards and can dump them to the laptop in about 20 minutes.
I upgraded the internal HD on the laptop to a 750gig version so I have plenty of temporary internal storage.
After the shoot I connect the laptop to my desktop as a firewire drive and transfer all the shoot footage to my raid.