hang them on the walls of your main area--where ever all your people will be. if anyone whines about you putting holes in the wall, remind them that filler/putty exist, and assure them you'll be happy to fill the holes, sand, primer, and paint in the event that your company goes out of business and leaves.

a bike inside is another open parking spot outside... and many places have a serious dearth of available parking so they should appreciate this.