URL in Launcher
You can use xdg-open:
Run gksudo gedit to get a root text editor, and paste:
#!/usr/bin/env xdg-open
[Desktop Entry]
Version=1.0
Type=Application
Terminal=false
Exec=xdg-open [URL HERE]
Name=[NAME HERE]
Comment=[COMMENT/TOOLTIP HERE]
Icon=[ICON HERE]
You can look for icons in /usr/share/pixmaps
Save the file in /usr/share/applications/, and logoff and logon for good measure. Search for the launcher by name withing the Unity dash and drag it to the launcher.