As published on Torsten Curdt’s weblog you can use IRC style commands on Skype chat windows.
Here is a list of commands which you can use on Skype :
/add [skypename]
/help
/topic [new topic]
/me
/history
/leave
/goadmin
/get creator
/get role
/whois [skypename]
/setrole [skypename] MASTER|HELPER|USER|LISTENER
/kick [skypename]
/kickban [skypename]
/get guidelines
/set guidelines [text]
/get options [text]
/set options [[+|-]flag] …
/setpassword [password] [password hint]
/clearpassword
/get password_hint
/set password_hint [text]
/set password [text]
/get banlist
/get allowlist
/set banlist [[+|-]mask] …
/set allowlist [[+|-]mask] …
/alertson [text to match]
/alertsoff
/call [skypename[,skypename,...]]
