For mass-uploading of files through a Hotel WiFi, my suggestion would be rsync to a shell (SSH) account of your choice. If you don't have one yourself, set one up on your home computer (and forward port 22 on your router/firewall) or ask somebody.

The great thing with rsync is that it checksums and skips files that already exist, so especially in a low-coverage area, this should be helpful. You could also use ImageMagick or similar to mass-shrink the photos for uploading to save bandwidth and time.

If you can/want to afford it, buy a MicroSD card that has enough memory for your photos + a MicroSD-to-SD adapter, so you can use the MicroSD in your camera and then put it into the N900 for copying - that's probably easier and less kludgy than a card reader.

Also, I'd suggest getting a cheap BL-5J replacement battery on eBay + a wall charger for it - this way, you can charge the original or replacement battery in a power outlet while still keeping the N900 near you (with the other battery in it).