There are many potential cell phone based applications but the firsn to get approved for Diabetes is iBGstar from Sanofi Aventis. This is a good compromise is using the dipstick based technology and then combining it with iPhone to read out the results.
All this ends up replacing is the little electronic device that used to be supplied as the little electronic device but the rest of the technology is very similar.
Look at the link below for more information.