EDGE is a variant of 3G that enables users to download data at speeds of to 240 kbps (3G in the UK is 384kbps) and uploads speeds of 120kbps.
The S710a is aimed at the American market while the Z500 is slated for Europe and Asia.
So far none of the networks have expressed a great deal of interest in launching EDGE in the UK.
Sony Ericsson also paraded a pair of Bluetooth headsets, the HBH-660 and HBH-300. Both are due to go on sale in September.