IIRC the T30 series of laptops draw a maximum of 72 watts. The iGO Juice (and the power systems on the airplanes) are designed to provide 70 watts.

Since the power figure is so close, there's a good chance that the plus-minus tolerance is within the ability of the Juice unit. I'd call iGo's tech support and verify (they do list a tip for many ThinkPad models including the T30, and I believe they test each machine before putting it on the list). The number is 800-474-7593, Mon-Fri 8AM - 5PM PST.

My Juice unit has performed flawlessly (my laptop only draws 47 watts). I believe the person who posted about problems watching DVDs had a laptop that well exceeded the +70 watt limitation.