From: http://www.contourdesign.com/US/

 RollerMouse Free3 features two new buttons for forward and back in most Internet browsers, 
with a lower click volume to not disturb your workflow. At 0.9” high, the RollerMouse Free3 
still boasts the lowest profile in the RollerMouse family, helping maintain a proper, ergonomic 
position. Its slim design fits perfectly with our Balance Keyboard. RollerMouse Free3 is ideal 
for users with varied hand sizes.

http://www.kvmgalore.com/shopping/product_info.php?products_id=2428

Convert legacy computer's PS2 keyboard/mouse ports to USB
Connect USB keyboard and mouse to legacy PS/2 computer
Connect legacy PS/2 computer to NTI USB switch
PS/2 Ports to USB Adapter
Model No. USB-PS2-R  

http://www.kvmgalore.com/shopping/category.php?category_id=4617&group_id=72&category_name=PS%2F2+to+USB+Converter&kartSess=2d32eaf97105d9b3b8d05924c81cd80d

Extend the Life of Your Legacy PS/2 Equipment - Connect a USB Keyboard and Mouse to a PS/2 Device.
Keep your PS/2 legacy equipment! The PS/2 to USB Converter, a small, plug & play converter, transforms PS/2 equipment from outdated devices to valuable tools for today's data centers.
PS/2 to USB Converter
Model No. 0DT60002