Even if you were to find fuser it is usually only available to root.

Er, that's not strictly true, any user can run fuser. I'm just a joe schmo user on a Solaris 9 box:

[vek@alyssa - /home/vek]% fuser -u .
.:     2053c(vek)    2017c(vek)    1351c(vek)
[download]