I have been studying Vietnamese for a little over a month, and I just want to say: cảm ơn! I have found the translation feature and dictionary features so helpful.
I also want to recommend (I think I first found it via vdict) www.mylanguageexchange.com. I now have a chat pal in Hanoi, she is a student in the same profession as my profession and we chat and text (mostly in English and some in Vietnamese) several hours a week. This has been extremely useful for both of us! (I managed to get unikey downloaded, another big help.)

For those learning English, I am sorry for you learning all the crazy verbs and pleural words my language has. But for those learning Vietnamese, I hope you agree that the tones, vowels and ng-sound are tough!