I've owned a My Charge 6000 for several years now with great results.
Besides the Apple interface shown, it has another built-in short (1.5 in) cable on the other side (not shown in the picture on the link) with a connector that has a mini USB on one side and a micro USB on the other. It also has a regular USB port on the top that you can use with your own USB cable to power your small recorders with. I've used both methods with great results to power my Tascam DR-2d and DR-1. It ran a DR-2d for at least 8 hours. I put the battery+DR2d+CA-Ugly2 in my jeans pocket (yeah, a sizable bulge but what the hey) and just ran all evening at a festival without stopping between acts, good for very low pro.
I also use it to recharge my Android phone. I can get about 2 good charges before it is depleated. When recharging my phone, the phone occasionally stops at 60% full (phone message says phone is overheating) but I believe that's the phone's fault, not the My Charge 6000's fault (not 100% sure though).
I agree with the previous poster though, that a larger capacity power source for the same or just a little more might be the better way to go. The size of the MyCharge 600 is about the size of the DR2D, so nice and small. Not sure how big the larger capacity unit is. I'd probably stay away from the Tekkeon 3450 based on others' experiences!