I've been using this as my startpage for about a week, and it's added a layer of convenience to anytime I'm in "research mode" about a topic. I can flip through Google, Twitter, Youtube, etc, and get a good all around feel for the prevalence of a topic, in a matter of seconds.
The filter function on the left searches through your list of search providers, but also instantly searches through Dashler's database of sites. You can specify part of a name, or a tag like "books" or "shopping" or "blog". (If you have a site you think should be there, please let me. I can add it right away.) In the "tools" section, you can add/edit/delete the search provider selected.
You can also add your own search provider. All you need is a URL with a "%q%" in it, which will be replaced by what you type in the search box.
Try it out, and let me know what you think.
Showing tips / help one line at a time might not be the best idea. For instance if you want to figure out what the filter does, you have to just click next over and over again and hope that at some point it will tell you.
Otherwise, this is pretty nice. Probably better than using a search toolbar. Though, I have quicksearches in my address bar for all of these, which means it's not really useful for me.
For instance if I want to research some programming topic X, I will go into my browser and type: "g X" -> Ctrl + T "w X" -> Ctrl + T "so X" to open tabs with searches of google, wikipedia, and stackoverflow (for instance). That's easier than clicking around on your site.
Now if you could display all search results side by side, it might be more interesting. And if you could create quicksearches for groups of that... So if I want to search Amazon.com, Amazon.co.uk, and Amazon.de at the same time and see results from all side by side (or in a grid layout if there are more than 3 sites). If you could do that, I'd totally use it.
If you want to keep it as a web site, I would make the interface (your search box, browser list, etc.) as unobtrusive as possible (remove all the daed space, try to move your entire search interface to a bar at the top or left perhaps, and create a results pane who's vertical scroll bar is flush w the right side of the screen -- this will create a much more comfortable and familiar experience for users.
Cool idea tho. You should hire a designer -- the current UI while functional definitely has that "engineer touch" :) (Not insulting, I have the same problem!)
You can add it to your list of providers by clicking "add" in the tools menu.
It would also be good if adding a new engine were easier. The language is a bit confusing. I think there should be an explicit "add another search provider to this list".
Keep it up! I'll be checking back!