Have a trip to Japan in afew weeks and thinking of bringing my beloved 3DS (original) for the trip.
Now, whilst i'm aware of the region locking for physical software, does anybody know if i'd be able to connect and download from their local e-shop? Would I be able to use local-play features on games like in Mario Kart 7? ... i'm not expecting much beyond a few interesting spotpass mii's but, are there any other incentives when taking a 3DS abroad?
Any replies appreciated America->Europe (vice versa) stories would be interesting also.

Streetpass Will work,
local-play Should word (or at-least it does with DS games), and
due to region-locking, you will still have access to your native eShop.

Hope this clears things up.

To answer your questions:
1. You can access the eShop out of your country, but it'll be the one your 3DS is programmed to go to. For example, I was able to access the NA eShop from my NA 3DS while in New Zealand (a PAL territory) this past summer, but I couldn't reach the PAL eShop.
2. StreetPass will work between 3DSs of different regions (provided you have at least one title's StreetPass features in common, of course). Local play, I'm not so sure, since I never tested it out when I was in Australia or New Zealand, but I'd assume if you can play with users from a certain region online, you can do so locally too.
3. Other incentives to taking a 3DS abroad - Nothing beyond what having your 3DS with you would be. Convenient 3D Camera for sightseeing photos, way to kill down time, etc.

many thanks, that pretty much covered all my thoughts