I have an older Melabs serial pin programmer which I purchased with a ZIF adapter. Though the Pic processors can be programmed in situ using the ICSP connect, if it is available, during development I find it is easiest to use a ZIF socket. To that purpose a ZIF adapter has been designed for use with the PicKit2. The ZIF adapter plugs into the PicKit2 ICSP connector and a switch on the ZIF board changes Pic number of pins, i.e., 28/40 or 20 etc.
At the moment I do not stock this board, but it is available from Batchpcb. The ZIF socket is available from several sources as well as the switch.