[Image: http://puu.sh/7cO6V/6fca57a8e7.png]
Actually it does, at the bottom this icon is called the reputation button. You can click that to +1 or rep someone for helping you or posting something that strikes your fancy. Use it however you want :)
An example is like this:
[Image: http://puu.sh/7cObz/be78a73dc8.png]
this will pop up you can type your reason for repping and click submit.
After you submit your rep, it will give you a pop up like this indicating the rep was successful:
[Image: http://puu.sh/7cOeO/a6b39b30f8.png]
If you try again too soon on the same user it will give you this pop-up indicating to rep some different folks before repping the same person:
[Image: http://puu.sh/7cOjo/7e0723b6ab.png]
or
[Image: http://puu.sh/7cOnd/22f39e3d85.png]