I am using an age-old laptop which runs 12.04 out-of-box.
HN, Please suggest age-new laptop that runs 12.04 out-of-box and it has a great portability, battery life and weight. I am a Linux developer and heavy on Vim, Git and Tomcat / LAMP stack.
I use a Thinkpad. Not only are they some of the best laptops around, they also have great compatibility for Linux and are well regarded by Linux-users - so support for new Thinkpad hardware is regularly added. Still, you'd be advised to search around first just to be sure they're compatible. I'm using one of their cheapest machines, a Thinkpad Edge E520. It's a great machine with full compatibility with Linux (running Ubuntu 11.10 with Gnome 3). The build quality is the best I've ever had and the battery life is 15+ hours (of fairly heavy use, not just when idle). It only cost me £340 (including a battery upgrade) :-)
I'm using a Lenovo LC2430HD that I ordered from LinuxCertified.com about a year ago. It has a Solid-State Drive, so no moving parts except the occasional fan and it's whisper-quiet. Good battery life too -- about 6 hours I think. It came pre-installed with Ubuntu 11.10 or so, and it worked perfectly out of the box, but I did re-install Ubuntu anyway with the Alternative CD because I wanted to encrypt the hard drive.<p>It's a great machine!<p>(Here's where I got it: <a href="http://linuxcertified.com/linux_laptops.html" rel="nofollow">http://linuxcertified.com/linux_laptops.html</a>)
I've got a Thinkpad T410 (integrated graphics) that's fully supported by OpenBSD 5.1; if it's fully supported by OpenBSD I'm very confident that it will be supported by Ubuntu. The Thinkpad X-series are very similar to the T-series and are much smaller and lighter.
I have a Toshiba Equium R630 and it works well. It's small and lightweight, although not quite ultrabook standard, and it feels very well put together. I think this model is EOL now, but you can find newer ones. Everything just works.