system font size

There is no way, currently, to globally change the font size in Lion for all fonts.

You can change the font size used for file and folder names, via View Options.

However, you can not change the size of the font used in Sidebar, menubars, alert messages, etc., other than by changing the screen resolutiuon.

Download the free application TinkerTool (not "TinkerTool System"), launch it, and select the Fonts tab.

Many people are suggesting this tool but it will not change the system font size, unless I have missed something.

I cannot find TinkerTool in the apps store. Do you know where I can find it??

It is not in the Apps store, but neither TinkerTool nor TinkerTool System will help with your goal in any case. This was confirmed to me directly by the company owner.

I have not found a solution for this and I have searched very hard. I have also been offended for unknown reasons during my search.