While the new and open buttons are easily recognizable, it's a little harder to know what the "box with blue arrow left" and "box with green arrow right" buttons mean at first glance. Tooltips would be an easy way to orient users.
Created attachment 1132 It's a start Here's a start for getting tooltips on the toolbar. I skipped all the stock buttons, though, since I haven't found a nice way to retrieve the strings.
In case someone ever looks at this patch again, GtkTooltips is now deprecated.
I think tooltips are not needed for the trunk version of squeeze as there is now a label under each icon in the toolbar.
squeeze is not maintained anymore, closing.