$ ln -s i_scratch_your_back you_scratch_my_back
$ ln -s you_scratch_my_back i_scratch_your_back

$ cd you_scratch_my_back 
cd: too many levels of symbolic links: you_scratch_my_back

$ perl -MData::Dumper -e '@s = stat("i_scratch_your_back"); print Dumper(@s)'; date
Tue Feb  3 07:31:40 PST 2009
$