I have a question and feel stupid asking this, but here goes....

Take for example the Senheisser EW 100 G2 system...are there any variations for different countries frequencies....example: if I bought this system in Canada, would it work in the states or elsewhere?

There are different frequency groups (A, B, C, etc.) available when you order. Sennheiser has a list of frequencies on their website somewhere I believe that lists the best group for your country.

A and B are suited for the US while "C" is no longer available as it has been sold off. Out of country I have seen "D" - you'll want to be careful about using wireless abroad as you can get yourself into a bit of situation of you are caught. It would be wise to always check the web and see if there are any issues regarding certain frequencies in other countries.

Here is the Frequency Finder for the US Sennheiser USA - Frequency Finder - Evolution Wireless (http://www.sennheiserusa.com/newsite/mat_dev/frequencyfinder/Freqfinder-ew.asp)

And a short demo on using the unit Sennheiser wireless Tutorial (http://www.dvcreators.net/products/sennheiser_wireless_movieframe.htm)