I'm working on getting a paper submitted to a Journal, and I discovered that Bibtex and Zotero disagree about how to express URLs. Zotero is one of my favorite tools, but it doesn't always escape special characters in its URL field when exporting to Bibtex format. It does a pretty good job on other fields, but drops the ball on URLs. This gives puzzling errors and causes big issues for users of Lyx (another great tool).
Rather than fix these by hand, I wrote a python script to parse the file and automatically escape the character Bibtex was choking on. I hard coded the file names, and it's not a nice utility, but I'm releasing it under the GPL and the CRAPL in case some one else needs it in a bind.
The tool is hosted here.
It reads a file "lib.bib" as input and outputs an escaped version as "out.bib"
If this helps you, or if you have an addition, leave a comment!