I have been thinking about this a few days ago. The cheapest that came to my mind, was to connect the two with a three wire serial cable (on the iMac side you need a USB-serial converter for a couple dozen $, like the Keyspan PDA adapter). If you don't already have a serial crossover cable, buy that too (or make one: TX-RX, RX-TX, GND-GND; DB9 to MiniDin in the case of the Keyspan PDA adapter). Then use a free terminal program like the venerable Z-Term to transfer files (e.g. Z-Modem transfer). Make sure to encode to HQX or BIN where appropriate (not needed for SIT compressed files).
Some other, more expensive (and convenient) possibilities:
- buy a USB floppy drive for your iMac, transfer by 3.5" disks
- use a Localtalk-Ethernet adapter (I think Farallon makes one; not 'cheap' tho)
[This message has been edited by 2far (edited 02-14-2001).]