End of 2008 Time Warner dropped usenet service, but it was pretty lousy anyway with less than a week retention.
For non binary usenet access Google (groups) works fine and is free to use via web interface.
For the net history challenged, usenet was what everybody used prior to web forums. There are something like 50,000 different interest groups all in a massive hierarchy of rec.games.rpg.wow type names (recreation, games, rpg, World of Warcraft, etc.). Messages are simple ASCII text with a fixed maximum length, and it worked great for a LONG time. Then somebody got the bright idea of converting a binary file into a series of linked text messages. This grew over time and now for a binary file of a DVD you might download 200k related text messages and various tools assemble them into an ISO to burn a DVD from.
Retention is how many days posted information stays on a given server. 30 days used to be common for non binary groups, binary groups with thousands of times more messages per day could be as little as a few days or a week. This was in the day of most Usenet servers running on spare machines at colleges etc. When the commercial providers showed up, the two things they offered for pay were greater speeds and more days of retention.
Generally how things work now people use special applications to access Usenet, and the application will keep track of all activity on the server, look for keyword content and only down load those files, down load all message header title info, down load all new info, etc.
Astraweb and the pay by the gig thing looks pretty good to me.
25 GB $10 Once-Off 25 Gigabytes Unlimited 50
120 GB $25 Once-Off 120 Gigabytes Unlimited 50