I was walking about and I loaded up Pokemon Go to check if there were any Pokestops in my area. There were two, but one looked different than normal. When I clicked on the Pokestop, there were floating hearts around it.
Are there anything special significance to these hearts?
The hearts floating around a Pokéstop signify that someone has deployed a lure module there. Therefore more Pokémon will be attracted there until the lure wears off.
There are also glacial, magnetic, and mossy lures which attract water/ice, electric/steel/rock, and bug/grass/poison Pokémon respectively. They can also be used to evolve certain Pokémon into their type specific evolutions. See here for more details.