Exactly -- WebCapTel only works in 3G (highspeed wireless) mode rather than EDGE (slower speed wireless).
In the times you're stuck in "E", you might be able to connect Safari over WiFi, and still be able to the phone over GSM/EDGE. Basically use two separate networks (talk over GSM/EDGE, while using Safari over WiFi)
Or you can still use WebCapTel with EDGE if you own two cellphones: One for talking and one for web browser. You can only do both at the same time in the same phone with 3G.
Also, for BlackBerry, I was able to try out a Bold recently. I think BlackBerry Bold will support WebCapTel, I tested it and it almost worked -- Bold supports the Web 2.0 AJAX technology that WebCapTel uses -- but there was a web browser bug on the Bold that prevented the captions from showing up. I think by Christmas 2008 we'll have WebCapTel working on BlackBerry Bold 3G.
It's bleeding edge definitely, WebCapTel was never designed for mobile devices so it is amazing it works at all on the iPhone and almost works on the BlackBerry Bold!
