You would like control your client (Can be done in Strongdc++, Zion++ and many others) from the net (partial control), or from a cellular phone... Then
Follow the following steps (Example with a Strongdc++ client):
Check the option: enable webserver in the settings/advanced section of your client
Then choose a port, a password and a user name in the settings/expert section
(By default, port 684, user name: strongdc)
The next step, you open your browser and use the following adress:
YourIp:port
When request you type your name and password.
Done... I guess a lot of users will love this ^^