The stuff i remember reading about these methods had 1) Always revolved being at the spawn loading chunk boundary 2) Severely limited in the amount of chunks you can keep loaded with these contraptions... 1) is hard in SMP because more often than not, you either get griefed a lot, have a massive spawn base that spans the whole loaded area, already have lots of players settled in the area (especially if chunkloaders are banned, because near spawn would be PRIME ground to set up automated bases). And 2) is about how it's very, very, very quirky how it works, about it's consistency and the means with which you can achieve these effects. In the best case scenario, you'd be able to get a plot at or near spawn and extend the chunk loading a little bit, by just a few chunks, enough to get the automation going. Don't really see it murdering servers...
EDIT: In any case, it probably doesn't even work anymore. I can't for the life of me find any google hits on the subject.
EDIT2: NVM, i found it. Pistons being used in a clock-like manner to transfer items from an loaded to an unloaded chunk, forcing the chunk receiving the block to be loaded, and doing this fast enough that all the intersecting chunks in the clock are kept loaded. Pretty spiffy.
And not that it will take to much space either. Reply's Would be greatly appreciated.