I find it hard to make sure that I deal with restarting software after I upgrade, so since I found the debian package debian-goodies contains a tool called checkrestart, that checks if any in memory applications is referencing old code, I converted it to using qfile and qlist from portage-utils.
The tool is very simple and basically does a lsof and look for applications that is accessing outdated disk files. It then checks what of those applications has /etc/init.d scripts and list those, if it can't find a init.d script, it list it with pid. Fx. spamd is detected as perl, so it gets listed as unknown. Code can be found at: http://www.arcdraco.net/~dragon/checkrestart
smime.p7s
Description: S/MIME Cryptographic Signature
