Windows 7 - Using the Start Menu to switch between running programs

First an admission. I'm a Mac user and an avowed keyboard shortcut enthusiast. On a Mac we have a wonderful app (prog in Winspeak) called Quicksilver, which makes it possible (among other things) to switch between running programs using the keyboard (i.e., without the hunt and click mouse nonsense). All I have to do is invoke a hot-key, type one or two letters (it remembers the apps I use most!), press Enter and BAM! I'm there. I find this so much faster than hunting for the right icon on the taskbar, or alt-tabbing through 10-15 apps to get to where I want to go.

Alas, in Windows (any flavor, be it 2K, XP, Vista or 7), if I do anything other than alt-tab to a running program, or click on its icon on the taskbar, I'm going to start another instance of that program, which means loading duplicates of all the resources that have already been loaded into memory!

Using Excel as an example, all I want is to hit the Windows key, type e x, hit Enter (assuming Excel is the first choice) and switch to the one (and only) instance of Excel that is already running. Is that really too much to ask? For the record, I have tried a number of Windows based Quicksilver knockoffs, and they all suffer from the same limitation. So it seems that trapping which programs are already running is an impossible feat under Windows

Windows Key+Tab

Or ALT + Tab for that matter.

I guess neither one of you guys read my entire post. I'm fully aware of what alt-tab and windows-tab do. Neither does what I want. Try getting to your destination quickly using alt-tab when you have 20-30 windows open! Can you say "alt-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab-tab" in less than a second"?

No, but I can hold Windows Key + Tab or Alt + Tab and it goes really, really quick. Maybe even quicker than 30 opened Windows in a second.

One for you:

CTRL+WINKEY+TAB and then click the app (program) want to bring to front.

(CTRL+WINKEY+TAB causes Flip3D to create a static list of all running apps).

you guys really aren't solving the problem at all.
akadmon wants to hit a button and type the program to open the current running process / make a new one IF a running one isnt there.

Anyway, from what I remember the guys behind gnome-do on linux were porting it to windows (ive not really paid attention to it though) I think thats the closest thing thing that currently comes to it.

EDIT:
http://www.launchy.net/

i think thats the gnome-do project ported to windows...

Launchy is one of the programs I've tried. It's as close to Quicksilver as it gets. Unfortunately, it too will launch another instance of a process instead of switching to it when it's already running.