Free today:
This Time Next Door by Gretchen Galway.
I stumbled across this book awhile ago because I totally have a weakness for geeky heroes.
According to the description, it was previously published under the title "The Geek Who Loved Me". Apparently it is part of a series, but it sounds like they are only loosely connected, so I'm going to ignore my OCD and read it without reading the first book.