I'll tell you, I really like using Barcode Essentials from Basis Design (http://www.barcodeessentials.com) on my iPhone. Each license is $300 and works wth a bluetooth Socket mobile handheld scanner (7ci) (about $225-$300). If you already have iOS devices then you'd be looking at $500 each which is about 1/3 the cost of the large Motorolas (we have 3 of those and stopped using them). The nice thing is, in a pinch, you can even use the camera on the iOS device if you don't have the scanner with you so you can do inventory at any time.
We have 3-4 licenses for Barcode Essentials, a few Socket scanners and then a couple of iPhones and a couple of iPod Touches that we do inventory with as/when needed.