DNA is sequenced using a method called shotgun sequencing, so essentially for every base pair of DNA there will x amount of reads covering it which are assembled together using a shortest common superstring algorithm. The acceptable rate of error is 1 in 10000 to publish a complete genome. Also 454 sequencing produces 250-500bp reads. The OP must be thinking of solexa or abi methods.

Actually most desks I've ever used, that were designed for use over an extended period of time, propped up to make writing drawing much more comfortable, and even then you'd clip your paper to the top to keep it at about eye height.