I use tab for aisle number. Would be useful to have specific field for this. To sort into aisle number I use numbers 1-9 and then A10, B11...F15.
2. Tag takes extra line - to save space would be better if it showed as a column.
3. Desparately needs search capability for pick list in order to quickly add items. Alphabetical sort not sufficient.
See HandyShopper for Palm which I used to use on my Palm Treo 650. Has all the features you need. I now need same on HTC Hero. This app is the closest I have found.