Yes! We produce one with a dictionary of over 200,000 terms. This is the largest and highest quality dictionary available.
http://popupchinese.com/tools/plugin
Additional Controls:
1. Highlight new words to add them to your dictionary.
2. Hit "A" to add any word to your online vocabulary list.
3. Hit "D" to change display options (traditional/simplified)
4. Highlight longer passages and hit "G" for the Google translation.