For learning Chinese, I’m using Qingwen on the iPhone quite a bit. It has really good recognition, but mainly it has word lists which are great. It also gives example phrases and the ability to use Handwriting for Chinese is terrific.
On the Mac, there are a host of resources that are scattered all over. Yale has the best explanation of what is available the most interesting thing being the Language input so you can input with handwriting. Also there is a text-to-speech voice you can download.
Then you can use Google Translate inline, just go to Google.com/translate and type in a URL and you are set!
And nciku.com does translation as well dynamically to both pinyin and english if you use Firefox
Other sites are http://www.mdbg.net