How can i improve my dsl speed?

I wanna know what kinda tweaks i can do to get my dsl running at max. any site that can help me tweak ythe router to the max? i have a Linksys BEFSX41 and it has a built in firewall.

A year ago i was forced with dial up until i begged the dsl company to try the so called un supported dsl in my home well the dsl installer comes and says it should work perfect and that people you call to order dsl just tell people what they are told is the distance limit. Well it worked great and my dsl company only has 3 speeds.... 128k 768k and 1.5mb Well we have the 768k speed and i use 2 pcs and 2 xbox 360 or 1 360 and a ps3 and this dsl has been great runs just like it should. I just wanna know how to maximize its potintal. BTW when i first got this dsl i they had my connection at 1.5 for a day and swicthing to 768k i didnt see a diffrence. anyway what tweaks can i do to my router/ setup?

128K $29.95
768K $42.95
1.5MB $55.95