Sugar and Maemo
(Maemo is the application development platform for Nokia Internet Tablet products.)
 Running sugar on Maemo
There was a successful attempt in running sugar on Memo using Debian chroot.
 Sugar and maemo
More people working on the Sugar desktop environment means more applications will be made and maintained in more languages. Programming or porting applications is a huge task, and translation into dozens of languages is not a small task.
One problem that we see a lot of in the open-source world is that we have too many projects. Just take a look at the number of open source text-editors or web content systems, and you will be astonished. There are dozens and dozens that work well, and hundreds or thousands that are alpha-quality. While nobody thinks that the Sugar project will be delivered alpha-quality, it is often better to add to an existing project.
I think we all want to see Negroponte's "I chose open source because it's better, I have 100 million programmers I can rely on." quote to come true. If we don't work together we are not reliable. We end up with 100 million programmers working on 35 million projects. Open source projects need to build bridges in order to better use our resources, we don't have the benefit of harsh monetary incentives.
To that end, could OLPC/Sugar use and extend the Maemo platform?
 UI tricks for small screens
The UI tricks used to work on the small screen are slightly different. Sugar appears to be focused on the idea of tabs, while Maemo is ostensibly focused on a single-app full-screen window and a maximize/menu button.
In fact tabbed Maemo applications like elinks show that the tabbed paradigm works efficiently in small form factor PCs like the Nokia N810.
They each have their advantages. For Sugar, the tab-bar can be seen as a more consistent version of the task-switcher (buttons for windows). For Maemo, the full-screen mode will let you use 100% of your screen when needed, and let the applications have tabs without confusing the user.
 Converging from both ends
Maemo is going from a big PDA screen and moving up into Gnome and GTK (on Debian). While the Fedora OLPC project (Sugar) appears to be going from desktop Gnome and GTK+ to fit on a big PDA screen. I think these projects are going to meet in the middle with similar platforms for similar hardware and screens, with the result being huge duplicated effort.
The main platform for Maemo is the Nokia 770, with a touch screen, dual 200 Mhz ARM CPUs and 64 MB of ram. The platform for OLPC has a keyboard & touch pad, a single 400 Mhz x86 CPU and 128 MB of ram. The screen size is also slightly different as the Nokia has an 800x480 while the OLPC will have a screen at approximately 650x480 in color mode.
The next-gen for the Nokia 770 will have a built-in keyboard. (The next gen model N800 has no physical keyboard.) Apparently the original author was more prescient than previously thought. Nokia N810 has a keyboard. Hoorah!
The N800 has 400MHz processor, 128MB ram, 256MB built in flash (for OS, etc) and 2xSD flash slots, built in web cam and powerful stereo speakers. It includes drivers for bluetooth folding keyboards.
The N810 runs a TI OMAP 2420 400Mhz CPU, 128MB DDR RAM, 256MB Flash formatted JFFS2, 2GB internal flash, support for miniSD and microSDHC memory cards, slider keyboard, GPS, VGA camera, bluetooth, 802.11b/g, 3.5 mm stereo headphone plug, and 4.13" WVGA display (800 x 480 pixels). It weighs only 226 g so a child could carry it in his pocket while carrying a jug of water on his head. It runs Busybox instead of GNU utilities, but GNU utilities can be installed along with man pages for a full educational experience. The included Debian operating system supports ext2, ext3, JFFS2 as well as other weaker file systems.
 More Mind-share to be the best
Unfortunately, on the road the projects are headed down now, applications will have to be different and translation tasks will be doubled. OLPC has had significant donations and Nokia has significant funds. Together they can pay pros to to do maintenance and translation on the basic platform. On top of this, a combined project makes the prediction that thousands of hackers will help make this the best light/mobile platform more likely to come true.
 Carpool to Success?
If the people at OLPC don't think that they can work to extend the Maemo platform, they could at least work with the Maemo project on the significant overlapping tasks. Just because you carpool to get to work does not mean you do the same job -- but you both benefit by taking a similar path to get there.