How many times have you hit F1 unintentionally just to have to wait for the Help to load and start. What a waste of time. Here is a tip on how you in AutoCAD 2006 and later versions or verticals can use CUI to change this behaviour.
Open the Customize User Interface using the CUI command or from the Workspaces toolbar select Customize in the drop down list.
In the Command List pane click on New.
In the Properties pane edit the Name and change it from Command1 to Escape1.
Change also the macro from ^C^C to ^C^C^C^P(ai_deselect) ^P. The reason is there are some commands that needs escape pressed tree times and this will also deselect all objects selected.
Expand Keyboard Shortcuts in the top left pane.
In the Command List pane notice that the Escape command is selected. Drag and drop it on Shortcut Keys in the top left pane.
Click on Escape in the top left pane.
In the Properties pane enter F1 as Key(s) value. Either click on the button with three dots or enter F1 and press enter.
Click OK to exit the dialog box.
Start any command and press F1.
Tip 1: Make a second command name it Escape2 and assign the Esc button to it. That way you don't have to press Esc more than one time.
PS. Right-click on Shortcut Keys in CUI has New as an option but it is not for the Shortcut Keys, it is for Temporary Override Keys.
For those with older version than 2006 add ["F1"]^C^C under ***ACCELERATORS in your acad.mns.