With all the cool hi-tech mobile field solutions available out there, I thought I would mention a very low-tech one.
http://walking-papers.org provides a way of printing out your maps onto paper. These paper maps have georeferencing marks on them. You take them out into the field, make your redlining changes and then when you come back into the office, you scan them and then upload the scan. The scanned maps are georeferenced onto the background map and made available for a back-office technician to digitize the data and red-lined attributes into the database.
Seems very simple yet effective. I'm not suggesting that Smallworld customers adopt this approach, but when thinking about mobile solutions I think it is good to understand the broad range of options and learn from them.