Most speed drops on DSL lines come from bad cabling !
1) Keep the cables as short as possible
2) Don't roll exceeding cables, it makes interference.
3) Check your connections and the quality of telecom cables too.
Besides that, people are right, most people/ servers on the Net can't upload as fast as you can download.
BTW I have an ADSL line with 3Mbit downstream and 128Kbps upstream.