i guess it would depend on how it was wired, if it is like a power strip then i can see it being something like acceptable, but even then??? PCMCIS 420W ATX Power Supply 20Pin Dual fan+4AC+3DC NEW - eBay (item 110354053224 end time Mar-21-09 17:48:35 PDT)
For whatever reason, they don't really seem to make them anymore--at least not commonly. Off-hand, and in my own unprofessional opinion, I don't know why. If I were to guess, it might be for safety purposes. I don't know what the retail is, but if it's $14.99 or even $30.00, that's a big indication to stay away, regardless of power output. I mean, I've seen PSU's with an extra plug for the monitor, but none that act as a power strip.
Yeah, they used to be really common of the old Pentium Pros and equivalent AMD K?. I've not seen one since a 6x86 machine. Quite a good idea if the psu has the beans... I just use a single plug with two 3 pn outlets now. Same result really.