A few weeks ago we should you how to convert a WordPress theme that was designed to show full posts into one that should excerpts instead. We included instructions on hacking your theme but someone showed us an oldie but goodie plugin called Evermore that might get rid of the need to hack your theme.
Here’s how it looks like once it’s activated:
As you can see above, it will even let you define the length of the excerpts by the number of paragraphs and/or character length.
The only catch is that it was last updated in Feburary 2009 but it worked well with our test WordPress 3.1.1 installation, so give it a try on a test site first if possible.
Get it: Evermore