Really whenever data stops working a quick airplane mode toggle does the trick for me everytime without a reset needed. I am at my desk all day and it sometimes just stops usually exactly at 5 when everyone leaves and is using their phones.
Wigetsoid2.x is a wonderful toggle widget app that you can completely customize the look the toggles. You can add Airplane mode, battery level, gps, rotation, and wifi hotspot. Really whatever you could think of. You can also Change color and transparancy of the widget. It is extremely well put together. Free and donate version available.
I hope this gets fixed with the Gingerbread update!