Emmanuel,

I am using the 8052.com SBC with a piece of soldering "universal PCB", similar to this one.
Inserting a row of headers and making a flat cable is a matter of seconds there. I was also making an "extension" from the RAM socket to a similar board, using some 10cm or so of a flat cable, running flawlessly with a '51 clocked at 22.1184MHz.

Eventually, when I don't need external memories etc. (i.e. circuitry requiring a lot of connections), I build a whole '51-based prototype on that type of board. One of those is running the lights in my house... ;-)

JW