I never knew of such things until today and walking over the bridge in Frankfurt with the Greek Inscription. You can read about them here. I foresee a wave of Love Padlocks from smitten Blippers.
The train to Frankfurt was great - I had thoroughly pleasant 45 minutes pootling through and thinking I'm rather pleased that I don't have an allotment that lies between the railway tracks and a great big chemical factory. I'm sure all the vegetables that come out of there are just lovely... Anyway, it was fine and I didn't get lost trying to get out of the Hauptbahnhof.
The area around the Hbf isn't the greatest (the first pub I saw had a banner that read "Six Nations HQ") and isn't for the faint hearted. There were some window displays that quite took the breath away. I shall dwell on that no further other than to say I'm pretty sure one was called The Dildorium.