Step 1: Download the debian packages from here.
For 32 bit users -
1. linux-headers-3.0.0-0300rc2_3.0.0-0300rc2.201106081532_all.deb
2. linux-headers-3.0.0-0300rc2-generic_3.0.0-0300rc2.201106081532_i386.deb
3. linux-image-3.0.0-0300rc2-generic_3.0.0-0300rc2.201106081532_i386.deb
For 64 bit users -
1. linux-headers-3.0.0-0300rc2_3.0.0-0300rc2.201106081532_all.deb
2. linux-headers-3.0.0-0300rc2-generic3.0.0-300rc2.201106081532_amd64.deb
3. linux-image-3.0.0-0300rc2-generic_3.0.0-0300rc2.201106081532_amd64.deb
Step 2: Once you have downloaded all the files, place them into a single folder. Browse to that folder from your terminal and then copy paste the following code into the prompt.
sudo dpkg -i linux-*
The execution will continue to install kernel 3.0 on your Ubuntu 11.04. Just in case kernel 3.0 mess up, do not remove previous versions. You can always choose from the previous versions in the grub.
If you have or happen to install this, then please comment on the power consumption and other pros and cons of kernel 3.0.