I've had a 100 for awhile and other SD card supported mobiles. Generally the radios has a fixed manner it deals with the SD card that does not include for lack of a better word "profiles" having different loads. Using the manufactures software or something like RTSystems programing software you can create different loads on the computer, write them to different SD cards with the appropriate naming convention. Load as needed from the different cards to the radio.
Personally I group area repeaters (cities) by channel number. Zero to 9 would be closest or most often used. 10 to 19 would be the next further out and well you get the idea. I forget if the 100 uses memory groups to organize channels into easily selected and used section. Maybe that's something else to look for.
Good Luck,
Mike
