By system bar do you mean wbar?
I don't find it very time confusing to go System Tools > Screenshot.
There are other options, such as:
- screenshot.sh can be run from terminal or window manager run box
- download and install scrot, which will give you command line options,
including countdown delay
- best option might be to install grabber, which has a desktop icon that loads
nicely in wbar, allows taking shot of entire screen or selected area