We like Lucid Lynx. That's the code name for Ubuntu 10.04, scheduled for official release at the end of this week. We're not doing anything deeply interesting with it yet; most of our day needs to go to conventional application-level development, and we have little time to spare for "play" at the kernel level. Like many others, though, we have begun to experiment with release candidates. First impressions: they're robust, the desktop has eye-candy, and, far more importantly, boot times are fast. Even without tweaking the kernel, the desktop shows up in fewer than ten seconds on conventional hardware. This is the kind of change that's easy to like.
One other point worth making now: 10.04 seems to be intelligent about encryption. One of our experiments is with a laptop that has an unencrypted boot partition, branching to GRUB as the boot loader. All volumes are encrypted. Select a volume, enter an appropriate passphrase, and boot-up proceeds smoothly. While there's nothing novel about this configuration, even when combined with a fingerprint authenticator, it's gratifying to have it work so easily. It ought to be a routine matter for all of us to protect ourselves from thieves, border agents, and other unauthorized users.