One problem you may find if you are not on broadband and you keep your connection live all the time is that your ISP will block you out after a set number of hours every month. Whilst most ISP's will boot you off after 2 hours you can still exceed their limits. I suggest you read their terms and conditions as there is usally a clause in there where they can boot you forever if you are considered to be abusing their system.
Anytime never actually means that. It means anytime you actually need to be online. One of the ISP's I used had a limit of 160 hours a month and any attempt to log on after that limit had been reached would prove fruitless.
Thankfully I get broadband early next month and so I hope that will be the end of the endless problems I have had over the years from tw@t ISP's who try to promote limitless internet access when in fact they all have arbitary limits which really give you a bad hair day when you can't log on anymore.