An excellent resource for realtime conflicts is:
The Court Reporter's Reference of Realtime Conflicts
It has about 2,600 prefixes, words, word parts, or suffixes that may form homonym (by, bye, buy), stenonym ("to the" and "tot"), and word-boundary conflicts ("sent review" and "sentry view"). Definitely the most extensive list of realtime conflict out there.
You can get a 10% off by going to the publisher's website for the book (click here) and using discount code: RW2VGPBU.
UPDATE: (April 2014):
Looks like an expanded Second Edition of this book has been published (click here).