Don't be sorry for all the questions -- this board is great for answering them!
First of all, you've got a great Camera -- I almost bought one. You also have LOTS of CF Card capacity, so even shooting at maximum resolution (or even RAW), you should have lots of room for each day you're out touring.
I haven't seen the Charger that is supplied with the G3, but I'm assuming it's very similar to the Charger that I have for my Canon S-50. If that's the case then it
will operate just fine on either 115 or 220 VAC. Be SURE to check the nameplate on the charger to confirm this though!
As you indicated, you will need Plug Adapters. The plug configuration for the U.K. electrical system is different from that of most European countries, so you will need an adapter for each. I usually carry at least two of each when I travel, which proved to be useful on my last trip -- one of the guests in the Hostel wasn't able to charge his Cell phone as he hadn't packed any plug adapters, so he borrowed one of mine for a few hours.
If you haven't bought Plug Adapters yet, you will be able to find these very easily, as I note that you're located in California. Check
www.magellans.com (they're in the Santa Barbara area, I believe) as they have an excellent selection to choose from. You can also buy these at any Radio Shack store or most travel / luggage stores.
With regard to your last question, I didn't have too much difficulty finding an outlet to plug the Charger in. One of the Hostels I stayed in had one outlet in our dorm room, and another just outside the door (easy to keep an eye on it from the room, with the door propped open); another Hostel only had outlets in the "common room" (there may have been some in the dorm room, but I couldn't find any?); the B & B's and Hotels were no problem at all. One of the other guests left his electrical devices at the Hostel front desk to be charged -- he asked them, and they didn't seem to mind.
I took only one spare battery with me (two batteries total), but on a couple of occasions I wondered if that was going to be enough. If you tend to use the LCD Monitor all the time, use the zoom and flash a lot and re-take a lot of pictures, it's easy to go through batteries. I will probably travel with three batteries next time. However I also have a Pentax 35 mm "backup" Camera just in case.
Finally, as far as downloading pictures at Internet Cafes that's not a realistic option in a lot of cases, as the Canon software would have to be loaded on each PC that you use (the instructions with my Camera warned me NOT to even connect the Camera to the PC until the software was loaded!!!). The other option is to use a small Card Reader, one that doesn't require driver software. Most Cafe owners are reluctant to allow people to start loading software on their machines. It's kind of an uncertain and cumbersome option and not one I would want to rely on while travelling.
It is possible to get photos burned to a CD at many photo shops from what I've heard, but I haven't used this option so can't comment on the costs, or how well this works. I saw a few shops in the larger centres in the U.K. that advertised this service in their display windows, but I was busy touring so didn't stop to enquire about the cost.
Since it appears that you've read a lot of the previous posts on this subject, I won't repeat the information here. However, to summarize some of the options I've considered:
> use a very compact Laptop (not practical to pack around, high "worry factor" in terms of theft or damage).
> use a portable CD Burner with built-in Card Reader, such as the Apacer Disk Steno (I would rather not have to pack around a bunch of blank CD's, burn them and then have to track down a Post Office or whatever to mail one copy home -- that detracts from my travel experience and is a bit of a "pain in the neck").
> use a Portable Hard Drive such as the FlashTrax unit (this is my most likely option -- it's compact and easy to carry, has good capacity, seems to be reliable with excellent after-sales customer support from what I've heard, and plays MP3's as well -- the only "downside" is mediocre battery capacity, but I can live with that, as I probably won't use the MP3 feature when I'm travelling).
I hope these few comments have been of some help. Good luck with this, and if you have any further questions post another note.
Cheers!!!