I was using Google Streetview of Florence earlier this afternoon when I found the following view.
It is on the south side of the River Arno, upstream from the Ponte Vecchio.
Supplementary note of 28 May 2011
The above link no longer goes to the correct place.
Please try the following.
End of supplementary note of 28 May 2011
Rotating around, there is a large poster using the word IMPRESSIONISMO in red sans serif letters and the phrase Dipingere la luce in white in a serifed face. Translation Plus translates that into English as “Impressionism To paint the light”.
Please note that the poster is landscape format and that all of the lettering is horizontal.
Zooming in there is a web address.
Searching in Google Streetview for Palazzo Strozzi shows that the Palazzo Strozzi is on the north side of the River Arno, not next to the river, and a short way downstream from the Ponte Vecchio.
Looking around from that view, there are four more posters. These posters are all portrait format, along the same theme. Some of the lettering is horizontal, yet the large red sans serif lettering has its baseline rotated, sometimes the lettering goes up and sometimes it goes down. Three of the posters have the white serifed lettering as well.
I found the following web page.
http://www.impressionismofirenze.it/Sezione.jsp?idSezione=56
There are some pdfs on the following page.
http://www.impressionismofirenze.it/Sezione.jsp?idSezione=33
William Overington
13 June 2009