The Slow Boat Experience: Advice for Travellers
From Chiang Mai we wanted to make our way into Laos. There are very limited options to do this:
1) fly ($$$)
2) take a 16 hour ride on a mini-van to Vang Vieng and skip out on Luang Prabang
3) take a two day slow boat into Luang Prabang - we went with this option
Advice #1: book the full excursion from an agency in Chiang Mai because you get better value than if you were to try to do it on your own. We paid 1650 Baht which included a mini-van ride to the border, accommodations the first night, dinner, breakfast, a lunch box and the two day boat ride.
Here is how it goes:
Day one, we were picked up from our guesthouse and driven to the border town of Chiang Khong. Along the way we stopped to see some hot springs (which are great to soak your feet in) and in Chiang Rai to see the amazing White Temple (Wat Rong Khun). We made it to the border where we checked into the guesthouse and were given dinner (included).

Wat Rong Khun, the White Temple
Advice #2: use the guesthouse service to get your Thailand exit stamps. To avoid having to wake up early the next morning and cue up for customs, you can pay 100 baht and your guesthouse will do it for you. They also give you all the necessary paperwork to fill out to get your Laos visa.
Advice #3: go buy provisions for the long boat ride. Bring drinks and snacks because there is limited options on the boat and it is way more expensive.
Day two, we got breakfast and a take-away lunch box (included) for the boat. Our stamped passports were returned but not before being accused of carrying a fake Israeli passport! We were driven to the border and then got on a rickety long boat and crossed the river into Huay Xai, Laos. After a long wait we got our visas which cost $US42 for Canadians and only $US30 for other passport holders.
Advice #4: do not listen to any touts trying to convince you to upgrade to a bus! They will tell you of the horrors of the boat and how expensive the night to come is. Not true! Just stick with the boat, it is an experience. You won't regret it and plus, you've already paid for it.
We were driven to the slow boat and we were off down the Mekong River. There were some very comfortable and reclinable chairs and most benches had cushions. There was even enough floor space to have a great round of UNO. The boat ride was only 6 hours (the aforementioned touts claim it takes 10 hours).

How many white people can you fit in one boat?
Advice #5: make friends, it will make the time go by faster. Sit beside the guy with the guitar and join the sing along or bring cards/games. The slow boat can be lots of fun!
We arrived in Pak Beng and were whisked away to a great guesthouse. All the guesthouses cost 200 baht and we had the cheapest beer to date. Again, the same touts promised rooms no less than 400 and expensive food. The only down side is that electricity shuts off around 11pm so the whole town is dead. It is a good excuse to get an early night.
Day three, we got breakfast and some more food for the boat (the baguette sandwiches are cheap and taste great). Then it was back on the boat. The second boat was a tighter squeeze but we got the floor where we read, slept and played games. We were on the boat for 7.5 hours but with the beautiful scenery and great company the time went by fast. We arrived in Luang Prabang with high spirits.

Views of the Mekong River
In conclusion: slow boat = good times