Yes you can. Mozilla Labs has a project called Prism (formerly Webrunner) that allows you to run a web browser like window without the standard web browser functionality. Apart from giving you a more convenient way of launching your web applications it also runs as a separate process than your ordinary web browser. This means that if your web browser crashes or is bogged down with all your tabs, your web application is still safe in it’s own process. Another feature is that you can reach your web application faster than via your web browser.
I’m pretty happy with it even though I have found one missing feature. I usually read my podcasts in Google Reader and when a new episode is available I right click the media file and saves it to my desktop. Unfortunately isn’t the save as option available in Prism. But anyhow, it’s worth trying out!
You can make shortcuts that launches the Prism application with your preset web site (in this case Google Reader).
I’ve tried it on Windows but it’s supposed to work under Linux and Mac OS X as well.
Update: I’m not currently using this since I found some problems. The most important is that I’m used to open up blogs I read in different tabs instead of reading them in Google Reader and I haven’t found any way to do this with Prism. I guess it would defeat the point somewhat…