My Android Dev Phone is able to display a pretty impressive collection of diagnostic GSM/UMTS data.
SImply enter the Field Mode by typing this into the Dailer app:


Now simply push the "menu\" button and select "test item\"
The following menu will pop up and allow you to get information about one of these items:

- GSM page
- 3G Reselection Paramters
- 2G Reselection Paramters
- 3G Reselection Status
- 2G Reselection Status
- Layer 3 RRC Signaling
- PRACH/RACH Information
- 3G DCH Status
- 3G Neighbourlist Status
- 3G BLER Status
- 3G Downlink Transport Format
- 3G Uplink Transport Format
- 3G DL RLC AM Status
- 3G UL RLC AM Status
- HSDPA CQI Status
- 3G Reselection Event
- 3G Dnlink Transport Format Comb.

Pretty awesome :)