All of the above, plus..
Downloading cannot be made faster. In a DCC send, the slower connection always takes precedence..even if you have a 1mbps cable connection, if you're downloading off of someone with dialup, it will go at 3-4kbps anyway.
You can speed up sends with 3 commands:/fsend on/pdcc on/dcc packetsize 8192
Bare in mind, these only sometimes speed up sends...and even then, it's almost unnoticeable
Happy illegal file sharin'