Write up your negative findings FOR FREE with F1000Research!
(from their blog)
“At F1000Research, we pride ourselves on transparency and openness, and we encourage the publication of all sound science – not just those studies that result in positive findings. That is why from now until the end of August, we are waiving the article processing fee for articles that report negative or null findings. Quote code NR13 for free submission when you submit your negative results paper.”
Additional info may be found here.