tfoote:
well, when i send data, it is in packets. Once a packet is finished, i start sending a new one. it doesn't stop.
Well that shouldn't stop you from still doing many independent sequential operations in your sketch. You don't need any kind of true multitasking, which is a overused term and does not even apply to microcontrollers. You just need to learn how to write correct program flow structure in C/C++, and learn how to avoid or work around any 'blocking functions' like the delay() function for example.
Lefty