Yes. There are a few things you can do.
Here's an example site (from the guys who do the SplunkTalk podcast):
http://bit.ly/splunktalkanalytics
Take a look at this video blog post:
http://blogs.splunk.com/2010/09/27/video-glimpse-into-splunktalk-podcast-analytics-insecure-login-da...
The gist is that you can use "insecure" authentication, and embed login credentials into the URL. Then, create a dedicated role for that user, giving it access to on the indexes, search commands, etc. that it actually needs. Maybe even assign a search filter. Also, create a dedicated search app, with just the dashboards you need, and make that the default for the user. Using a separate, stripped-down search head can also help limit your attack surface.
If you want to use always-on displays, the timeouts can be a problem as well, so see this thread:
http://answers.splunk.com/questions/7233/user-specific-browser-session-timeout
Remember the common tradeoffs between security and usability apply, so doing this of course involves a bit of additional risk. Provided you're ok with that, this should get you started.
