A pin punctured my tyre. Should I only replace the inner tube, or patch the outer, rubber tyre? Today I managed to run over a flat heat board pin, and my tyre got punctured.

I will change my inner tube tomorrow, because it's not that expensive and I find it easier than patching it up.

My question is: Should I be concerned that the outer rubber tyre was damaged? If so, would applying a tyre patch on the interior of the outer rubber tyre do any good? Or would it make things even worse for the new tube? My fear is that the hole means a weak spot in my tyre, and that the tube would break.

Thanks for your help!
The size of the puncture really dictates whether a new tire is in order... that being said, if you patch your tube and inflate the tire (the one with the puncture) you want to make sure the tube is not exposed through the puncture hole.  

If you need to ride and the tyre is questionable... an old trick is to put a dollar bill or power bar wrapper on the inside of the tire over the puncture hole... then install the tube and inflate.  The pressure from the inflated tube will be distributed across the wrapper resulting in an extra barrier keeping the tube from protruding.  

Good Luck.