Two suggestions from me, hopefully not too demanding:
1) Adding a default translation language for each user upon login.
Every time I log in, the suggested language is auto-detect; auto-detection works Ok but not perfectly, especially for shorter sentences, and I have to change the language every time, which is something of a nuisance. Furthermore, even if my language is remembered after the first page, whenever I open a page on Tatoeba from an external page such as http://bit.ly/tatoeback which I often use the language gets reset back to auto-detect.
2) Adding some sort of keyboard navigation on the site.
Yesterday I translated a couple hundred sentences and now I have some pain in the right shoulder, since each time I complete a sentence I have to reach for the mouse, scroll down till the next sentence, click on the 'translate' button above it, then move back to the keyboard and start typing. If there's some way to automatically start translating the next sentence on the page - sorta like in Excel where pressing 'enter' sends you to the next cell - I'd appreciate it tremendously, yup :)
Ok I know next to nothing about making websites so I'm not quite sure how feasible these suggestions actually are but I'd be very thankful if the admins consider them. Cheers! :)