ReiserFS is "fast"

wouter@rock:~$ time dd if=/dev/zero of=sparsefile count=1 bs=1k seek=1G
1+0 records in
1+0 records uit
1024 bytes transferred in 0,522148 seconds (1961 bytes/sec)

real    6m26.308s
user    0m0.011s
sys     1m13.094s
wouter@rock:~$ time rm sparsefile

real    3m14.809s
user    0m0.001s
sys     1m33.124s
wouter@rock:~$ 

Hell yeah.