Is there an LZX-like archiver for the PC???

[Homer]

Don't quite understand what you are looking for, but I use on the PC "Alzip" (http://www.altools.net) which is free and can do alz, ace, arc, arj, b64, bh, bhx, bin (hex files), bin (CD images), bz2, cab, ear, enc, gz, ha, ice, iso, jar, lcd, lha, lzh, mim, pak, rar, tar, tgz, uue, uu, war, xxe, z, zip, zoo, 7z, and 001files. I think it does even more than that but you'll have to have a look. Just a little something I discovered while working in South Korea :-)

[adolescent]

"File Grouping" is better known as solid compression and as Piru says, RAR has been doing it for years (as well as gz'd TARs).  

One of the newer, better archive formats is 7z.  

http://www.7-zip.org