
8GB Eye-Fi Pro X2
Get one of these cards. They are awesome.
- It automatically geotags your photos (bonus for travelers)
- It has WiFi built in and can upload to your favorite sites automatically
- It can be paired with a mobile device (iPhone, iPad, Android) without a computer

Canon S95
This is the camera I use. It is also awesome.
- Small form factor
- Full manual controls / automatic by default
- Shoots RAW
I travel a ton, here's my process:
I shoot my pictures with my with my S95 using the EyeFi card. They are automatically uploaded to my laptop via WiFi when I get back to wherever I sleep. If my laptop is unavailable the card is able to upload directly to the web using any open WiFi network. For a nominal subscription fee you can purchase access to private hotspots worldwide. If there's no WiFi available and I'm without a laptop I can upload the photos to my iPhone (or Android) using the EyeFi app. Depending on what country I'm in prepaid 3G data plans can be very cheap and I can use my phone to back the photos up to any number of online services.
It usually never gets to needing to use 3G for uploading as I manage to find free wifi almost everywhere in the world. At least every week when I'm traveling in remote places.
I'd recommend uploading to Dropbox. If you don't want to pay for the premium plan every month you can use their referral program to increase your available space. They also offer double space for students (.edu address required).
There's also a really nice feature called "Endless Memory" that automatically deletes photos from the card that it has confirmed are backed up online. You can configure it to make sure you always have a certain amount of space available.
To address each of your points from above:
If someone steals my camera, I do not lose all my pictures
They should be backed up (at least most of them). When the thief gets near wifi and takes some pictures you might get lucky and have a geotagged photo of the criminal.
I have more space on my SD card if I can delete old images from time to time
Endless memory does this for you automatically.
I have a backup if the SD card fails for some reasons
The photos should be online already
I do not lose all my pictures if I forget to take my camera with me
Same as above.
Now I have some problems:
We are talking about storing around 20'000 pictures, each about 6 MB data, so I need a place to store 120 GB data. That's not a problem on my personal computer, but it is more problematic to get such a amount of data hosted
Get a Flickr Pro account, upload the photos privately. It allows for unlimited photos... but not RAW. You can also pay for Dropbox.
Somehow I have to transfer the data. Normally I would just ftp it, but since I'm in very remote areas, I'm not sure if there is always a FTP client or a CLI available.
You'll need wifi, if you have lots of photos and they're big it will be slow but there's no way around this besides getting a faster connection.
I'm not sure if all computers I will have to use during my travel have a SD card adapter or at least a USB plug.
You don't even need a computer.