HI ... Yes the question that you ask is a very CURRENT practice to IMPLEMENT a UART when there is no SPECIALIZED hardware to do it.
AS the last message reveals .This is called a SOFT UART . is only HALF DUPLEX .. .. Depending on the MICRO used . generaly a very INEXPENSIVE one .. But almost all of them have a TIMER .. You need to use the TIMER to know when is time to sample the line again ..
The first bit is usually used to trigger some an interrupt to let you know that a byte is on it's way .. ..
there are variations of this of curse .. If you take the PIC12CXX this chip wont allow interrupts .. for evry bit .. so you have to poll the TIMER0 to see when is time to sample the line .. The MSP430 on the other hand relay on TIMER interrupts to sample the line so . You don't have to stop whatever you are doing to process serial data