Hi Josh,
not an expert, but I thought it may be an improvement of sorts if clicking a link opened a separate tab by default.
From my perspective as a forum user there is only one click required to reach the new link and keep the page open if links are set to open in separate windows.
From SEO perspective, opening external links in the same window usually decreases retention rates.
Just a thought… but perhaps people with more knowledge would comment…
regards
Daniel
UPDATE: this feature is now available. If you want external links to open in a new tab, go to your settings and check the box that is labeled “Open all external links in a new tab”.
The text below is from 2013, and is outdated. Opening links in new tabs can now be turned on in the user preferences.
This is a tough decision in web design, because different people prefer different things.
Most usability experts recommend not using target=“_blank” because it overrides user preferences. There is no consistency across the web about how websites do that so one never knows what will happen until clicking. 
I prefer to leave the decision up to each user:
If you want to open a new tab you can hold the ctrl key down when clicking. That opens a background tab in Firefox or Chrome. If you prefer foreground tabs instead of background tabs, you can change that in the browser settings.
If you prefer a link to open in a new window, you can hold down the shift key when clicking on the link.
If you accidentally close a tab, press ctrl-shift-t.
If you accidentally close a window, press ctrl-shift-n. (Firefox only)
To move between tabs use ctrl-tab and ctrl-shift-tab on the keyboard.
To close a tab, press ctrl-w.
If you use those shortcuts, every link on every website will open in a predictable way.
If I force the links to open in a new window, there is no way for users who prefer links to open in the same window to override the new window, while if I leave it like this, people can use ctrl or shift when clicking to open the links in their preferred way.
a _blank target as an attribute of your <a> tags would be helpful in navigating through links , It would open clicked link in new tab instead of pulling us away from artofmemory forum everytime, but Maybe I am a rare 
[Edit: I merged some of these posts here from another thread, because they are about the same topic.]
I tend to avoid target="_blank" in most scenarios, because it takes control away from the user. There are standard shortcuts to control link behavior on all the major browsers:
ctrl-click (or middle-click) to open links in a new tab. shift-click opens links in a new window.(There are some other useful navigation shortcuts listed here, like ctrl-tab and ctrl-shift-tab.)
Using target="_blank" disables the ability not to open links in a new tab, and the behavior becomes unpredictable, because only external links will do that and most people won’t see which links are internal or external until they click.
I occasionally use target="_blank" when the page has some kind of state on it that might not get saved if the URL changes, but usually leave the decision up to each user.
Here are a couple of article about it from a web design perspective:
I didn’t know about the internal links not responding to it! Thanks! I understand why you don’t have them now.
But I never want a link to pull me away from this forum though; it feels like closing a huge encyclopaedia after each article even if article is a page or two away 
Unfortunately, the open in new tab on my tablet is a pain… Am clicking Back a lot since I’ve fallen in 
with this place!
It’s a difficult decision when building websites, because everyone has different browsing techniques.
Are you using an iPad? I’ve never tested this site on an iPad, but I should do that soon to see what it’s like.
I do have an IPad but I haven’t been here with it yet, I’m using a old nexus and normally it wouldn’t be a problem but my present condition really affects my ability to press long on the screen these days. I’ll think about it when I get back to my iPad, and keep you posted on how everything works on it.
poor iPad Al alone in a gloomy storage 
I just had an idea. If it’s an Android tablet, you could install Firefox for Android. It’s the only mobile browser that allows browser extensions, and there is one that might be able to open links in a new tab. If that plugin doesn’t work for you, let me know and I could look into other ways to override it on Android.
(I don’t think there is a way to do it on iPad or in Chrome on Android.)
Wow, thanks a lot, I didn’t even think there would be Firefox with extensions on android. ! Checking it out! Thanks a million!
This is a great forum. Thank you for all the work you do!
I just stumbled on this old thread. In case anyone is still looking for this feature, you can turn it on by checking the “Open all external links in a new tab” in your settings.