Do you want to try Mono but not install it on a Pc?
Do you love the Knoppix Linux distributions and its extreme facility to booting on every machine (I love Knoppix, I'm a Knoppix fan from years now)?
Ok... this is the tool for you! 
Jon Galloway points me to this wonderful tool, exactly the tool I was waiting for (I remember some months ago a big discussion on my blog about this): a Knoppix Linux distribution with all the Mono environment installed: Monoppix.
This is now a public preview only intended for testing and feedback prior to the official release, but seems really promising. I want to test it soon. 
The ISO to download are located HERE.
Now I hope only that the Mono Team will release the complete support for Windows Forms soon...
According to a news on LinuxDevices, the latest embedded market research data from Venture Development Corp. shows that Linux is now firmly in first place as the operating system of choice for smart gadgets and embedded systems.
Will be really true? Ok, the market research must be always taken carefully, at the moment I don't know if Linux is growing more than Windows CE/Mobile on the embedded devices world, but surely it has all the possibility to be the number 1 OS for the embedded.
The open source nature can help this result... the manufacturer can totally customize their OS, adapt it for your hardware and I think that the hardware requests (memory) could be reduced at the minimun (you can have a complete kernel in few Kb). This could be a key of success for the mobile world.
However... only the time will show us if the result above are really true.