I ran Cat 5 through a buried black poly pipe to get from the router in the barn (where the DSL comes in) to a router in my house so we could have a connection in the house - just under 300'. I used a shop vac to suck a length of poly baler twine through first, taped a small plastic bag to the twine to get it to seal in the pipe when I sucked it through.

Pulled the Cat 5 with the twine, used lots of yellow wire pulling lube, worked ok. I would suggest you don't wait until winter though - I did the project on a December night at about -20C, enlisted the help of my 12 year old daughter and got it done. Was not particularly fun.  No wifi in the house was a good motivator to get her to help.