Hotbar is a program which graphically enhances your web browser using skins. A Hotbar skin replaces the gray area at the top of your browser with graphics. Here's an example:
I run this site http://hotbar-skins.com with my free time at my own cost because I really enjoy making graphics. I use Paint Shop Pro 6.0 and Photoshop 6.0 to make the hotbars. It's nice to not have to stare at the same gray browser color when surfing the net. With hotbars, I can change the picture as quickly and as many times as I want. The only thing is, you have to put up with a small space of ads on your browser bar. Right now, they only work with PCs and Internet Explorer (they used to work with Netscape). I don't make them as often as I used to, but right now, my site averages about 20,000 hotbar downloads a month.
As far as the engine swap...I really don't know the difference between the 2v and 4v. I got all the graphics from ducati.com and thought it would look cool on the hotbar. ;D