Taiwanese gadget maker Asus made waves in the ultra mobile PC space this week, as its Eee PC hit shelves in the US.

The gadget puts pressure on the likes of Nicholas Negroponte’s OLPC project and Intel’s ultra mobile PC initiative.

For $400 the Eee PC packs a 4GB SSD (solid state drive), 900MHz Intel Celeron M processor, 512MB of memory, a 7″ screen, full keyboard, 100Mbps Ethernet, modem, and wifi, as well as a bunch of expansion ports.

The unit runs Xandros Linux but handles Windows XP just as well. Cheaper configurations with a smaller SSD or minus the built in web cam are also available.

2007 has been a year for activity in the mobile internet space. With stellar mobile penetration going on in the developing world, the first experience of the internet many inhabitants of emerging markets are getting is over wireless.

Industry body the GSM Association (GSMA) is spearheading an initiative to research consumer trends and the mass market potential for notebook PCs with embedded 3G mobile broadband, while other players such as Intel and Nokia are developing their own mobile web gadgets.

And Linux is the operating system of choice for such devices. Moblin is an umbrella, open source project focused on the development of Linux for Intel-based devices and will host various community-based projects such as Ubuntu’s Mobile and Embedded Edition, and Red Flag’s MIDINUX flavour of the operating system, both of which are targeted for such devices.

Menlow, due out in the first half of 2008, is Intel’s first platform designed from the ground up for MIDs and UMPCs. Featured on the Menlow-based designs are optional standardised capabilities such as wifi, 3G and WiMAX to enable more of an always-connected experience.