The shift key increases the speed. So, if you are moving and raising a large section, you can move across the map faster. I use the shift key to mover around areas of the map, and when zooming in or out. Sadly, it dont seem to allow you to raise objects any faster as nice as that would be!
Case: Antec 900, Mobo: Asus Sabertooth 990FX, CPU: AMD T1100 Thuban 6 core @3300 ghz stock settings, COOLER: Thermaltake Frio, MEM: G Skill Ripjaws X series DDR 3 @ 1866 9-10-9-28, HDD: 2 Western Digital caviar Black 750 Gb set in RAID 0, GPU: Saphire HD 6950 flashed with 6970 bios, PSU: Corsair CX750M, MS: Cyborg Rat 7, KB: Logitec G510, OS: Windows 7 home premium 64 bit.