Straight from the keyboards of the Lonely Planet team…
Perfect gift: Personalized love-locks or pastel padlocks. Or perhaps a Grateful Dead-inspired lock (thanks Etsy). At scenic spots around the world, romantic couples scribble their initials on padlocks and affix them to bridges, hoping this symbol of their passion will last forever (or at least until the local council arrives with bolt-cutters). Love-locks are ideal for starry-eyed travelers, and maybe they’ll surprise you by tearing themselves away from their torrid embrace for long enough to secure their hostel locker or bike. Thanks Lonely Planet for the tip!
http://www.lonelyplanet.com/blog/2011/11/21/gift-inspiration-5-perfect-travel-presents/