Linux Poison posted a tutorial about installing Kernel 3.0 on Ubuntu 11.04 (Natty)
Besides a new version numbering scheme, Linux 3.0 also has several new features: Btrfs data scrubbing and automatic defragmentation, XEN Dom0 support, unprivileged ICMP_ECHO, wake on WLAN, Berkeley Packet Filter JIT filtering, a memcached-like system for the page cache, a sendmmsg() syscall that batches sendmsg() calls and setns(), a syscall that allows better handling of light virtualization systems such as containers. New hardware support has been added: for example, Microsoft Kinect, AMD Llano Fusion APUs, Intel iwlwifi 105 and 135, Intel C600 serial-attached-scsi controller, Ralink RT5370 USB, several Realtek RTL81xx devices or the Apple iSight webcam. Many other drivers and small improvements have been added.How to Install Latest Kernel 3.0 on Ubuntu 11.04 (Natty)