The Nokia N800 default browser is the Opera. It is a nice and decent browser but still it has some flaws, eg Google Reader is unusable due to it
One alternative to the Opera is the microB, a mozilla based browser  with the new Gecko 1.9 layout engine . The MicroB is beta, has some flaws, but still has some advantages over the Opera. Google Reader is fully usuable as it is on your desktop PC, therefor Google Maps is broken, which works on the Opera. Even some multimedia sites for mobiles like the ZDF Mediathek  (ZDF is a german TV station) won’t work on the MicroB, but do on the Opera.
Do you want to switch between Opera and MicroB, depending on the website you want to use? Well thats possible and even promised by maemo , the developers of the MicroB, but the „Set Engine“ just doesn’t show up in the browser application menu.
Well, it’s a quite simple task to make this button visible. The basic idea is to edit
/home/user/.browser and set
hidden=true. Therefor you open your XTerm, start vi and edit the file. If you don’t know how to do this, just follow these instructions:
- Surf with the N800 to maemo.org/downloads/product/osso-xterm-advanced , click install and follow the shown instructions. Now you have installed the „X Terminal“ application, which you can find in „Extras„.
- Close all browser windows
- Start the „X Terminal“ application
vi /home/user/.browser. This opens the „.browser“ file in the application „vi„.
- Press the hardware button „Escape“ (the on with the curve arrow) once. Then type
:i(Shift, then :, then i, without spaces). Now you entered „insert mode“ in „vi„.
- Use the harware arrow-keys to navigate to the end of the line
hidden=false, delete „false“ with the backspace-key of the virtual keyboard and replace it with „true„.
- To save the file press the hardware button „Escape“ once again and type
:w!(Shift, then :, then w, then Shift, then !, without spaces).
- You can close the „X Terminal“ now and open the browser. At the bottom of the browser application menu is the „Set engine“ button.
To switch beween the browser engines you have to select one of the two engines from the „Set Engine“ menu (MicroB is always highlighted, just because of the alphabetical order), close all browser windows and the next time you’ll open a browser it starts with the selected engine.