Do you find that using anchors leaves some content hidden or cut off by your fixed top menu? I did, but I figured out how to fix this issue - Warning - it requires hacking your K2 component JavaScript file. Here's how...

File: components/com_k2/js/k2.js

Find: section labeled as "Smooth Scroll"

Add: "- 70" or whatever number works for your template fixed menu

Also: add a comment to remind you what/how you hacked the file

The result should be...
scrollTop: $K2(target).offset().top - 70 //HACK: added - 70 to compensate for fixed menu

Joe,

We really need to talk about phrasing.
K2 Hack will make a lot of people (including my self) nervous about being hacked.

On the other note, this is not even a hack. You can override the js file.
Simply unset the file in the template and include your own copy.

Finally you can make this dynamic with jQuery 's height() function.
api.jquery.com/height/

You can dynamically calculate the offset with the use of that function.

Let me know if you need an example.

My apologies @Krikor, I did not mean to cause a scare by using the term "Hack."
My goal has always been to provide non-coders such as myself the tools to take their K2 website to the next level...that's all.

I did not know you can override JS files.

I just tried it, but it did not work. I placed the K2 JavaScript file here...
/templates/MYTEMPLATE/html/com_k2/js/k2.js

But the following file is still being rendered:
/components/com_k2/js/k2.js?v2.6.7&sitepath=/

What am I doing wrong?

Here you go: www.joomlaworks.net/forum/k2-en/39127-solved-how-to-unset-k2-js-file#136273

For adding scripts, use this function: docs.joomla.org/JDocument/addScript

Thanks @Krikor