Results for me (as a German) when traveling in the US are varying.
Those sites (say abc.com, scifi networks, fox on demand etc.) which are checking the IP to determine whether to grant access to their (free) online-on-demand video don't allow me in when at home (in Germany) but let me in once I am in the US and connecting via a local LAN / WLAN there, as then the IP address is one from the allowed zone (the US). Guess their should be a way around that check from Germany but never tried (afterall you "just" would need to disguise yiour IP-address).
Regarding iTunes: iTunes allows everyone around the globe to browse every iTunes store from everywhere (there is a little drop down menu at the bottom of the shop's front page from which to access the various versions). Alas, shopping is only possible in the shop for which a user has set up an account. A user can set up accounts in various international stores (say the US one and the UK and the German one or even more) and use them all on one PC/laptop. But to set up an account in an iTunes store a user has to provide a (home) address in the according country and provide a local payment method from that country, usually a credit card with a billing address in that country. The way around this is - as described manyfold on the web - to buy iTunes gift cards from the country whose iTunes store you are interested in if you don't have a credit card from that country (e.g. as a German I would have to buy US iTunes gift cards if I want to buy any of the interesting Disney releases on iTunes). Each iTunes gift card is bound to the iTunes store of the country it is officially sold in by Apple / Apple's partners. The only thing is, when setting up the account using the gift cards as payment method the user still has to present a valid local address - alas that is (at this point) not cross checked by iTunes, so one may provide any address.
Please note that I am NOT endorsing this method of gaining access to iTunes stores not destined for your country. Also, please understand that the general terms and conditions a user agrees to PROHIBIT such behavior. However, there seem to be many fans annoyed by the actions of labels such as WDR limiting interesting releases on iTunes to the US stor and therefore choosing this way - again due to decisions of the powers at labels such as WDR onto which e.g. Randy has no influence due to their prior signed international agreements giving away rights to certain partners...
Yours
Dirk