sucky internet connectivity

My phone line's developed a line noise problem. It's hard to get online; most times when I do get online, my connection slows to a crawl within 5-10 minutes, and then I'm downloading at like 100 bytes/sec. If that. My cell provider recently started their GPRS service, and they offer unlimited usage for a flat fee. I've used that a lot in the last couple of weeks, but their service isn't very reliable. It's slower than dialup on average, I sometimes get disconnected randomly, I can't use the phone while using GPRS, and they have a very small number of ports open (telnet, smtp, dns, http, pop, https, and irc), which makes it inconvenient, Still, I can use it for hours on end. No one offers good residential broadband in my area. One place offers a 256kb/s DSL link for like $15/mo, but they have have extremely low traffic caps.