Here is a step-by-step tutorial on how to download the current version of Blender from the website and replace the version installed from the Software Center with the one that you downloaded. I hope this is what you wanted.
1. Get Blender
Open your browser and go to http://www.blender.org/download/get-blender/ . Download the appropriate version for your computer, 32-bit or 64-bit. If you don't know whether your computer is 32-bit or 64-bit, open a terminal (Ctrl+Alt+T) and run the following command :
2. Extract Blender
Open Blender in your downloads folder, right-click on the file you downloaded and click "Extract Here". Once it finishes extracting, move the folder containing Blender to your Home Folder and rename it "blender" for ease of moving it later.
3. Uninstall the current version of Blender
Open a terminal by pressing Ctrl+Alt+T. Type this command set:
sudo apt-get remove blender .
4. Copy the Blender files to where they need to go
Open a terminal. Type
ls to see what files are in your home directory. There should be a folder called "blender". If there is, run the following command. If not, rename the folder and try again. If there's no folder at all, go back to step 2. Command:
sudo cp ~/blender /usr/lib/blender -r
This will copy all the files in the blender folder to /usr/lib/blender.
5. Verify that the files copied properly
Open the file browser by clicking the "Home Folder" icon in the launcher. Click "File System" on the left side, then open the folder
blender. See if there's anything there. If there is, move on to the next step, if not, repeat the previous steps.
6. Open Blender
Open the Blender application. Right-click on the icon that appears in the launcher for the program, and click "Keep in Launcher".
Ta-Da! This is the best you can do to install the current version of Blender. You can redo these steps as many times as needed when a new version of Blender comes out. To remove everything in the blender folder so you can do these steps again, open a terminal and run these commands:
sudo rm /usr/lib/blender -r . This is the best you can do, it keeps the blender files in a safe place, and gives a launcher with which to open it. You can't install the current version Blender other then this way in Ubuntu 11.10, however 12.04 will ship with Blender 2.61. For more information see this launchpad post: https://answers.launchpad.net/ubuntu/+source/blender/+question/186716 and this one: https://bugs.launchpad.net/ubuntu/+source/blender/+bug/915248 . Hope that helps!