I'd pay the price of an average magazine subscription just to be able to change all my magazine addresses in one shot. There are currently about 8-10 I read regularly and a few others I often leaf through, and as I'm preparing to move, changing each of these one by one is a tedious headache.
Approval_matrix_dogsterThere used to be a service offered by the US Postal Service called OneSwitch through a partner where they'd do exactly that - change most of your subscriptions, and then try to get you to renew them for years in advance at a decent rate. It's why I'm locked in with New York Mag through 2009 (and, as of now, I'm happy to stay with them for the decade). That service is no more, but I'd love to see someone pull this off. I, for one, would even pay for the convenience.
(As an aside, some magazine sites ask you to enter your subscriber number on the magazine label. Yet some magazines often come in plastic wrap bundled with something else, and the plastic gets buried in the trash long before I'd think to save it. There is much room for improvement in the subscription renewal world. Another pet peeve: subscriber numbers that are impossible to decipher, like NY Mag's, which asks you to enter a 9-digit #, but the exact 9 digits are sandwiched within a string of about 16 of them, and it takes some guess work to figure out which 9 it wants. Now you can see why I'm willing to pay so I never have to do this again.)
(One other note: kudos to Time for doing it right - I've been changing my address while writing this post. When I logged in to Business 2.0, not having the magazine handy, it not only found my address on file without any guesswork on my part, but it also offered to change my subscriptions to Entertainment Weekly and Fortune - a time saver, even though I would have just let USPS forward those. Conde Nast wasn't quite as kind in allowing me to switch both Wired and The New Yorker at once; despite repeated efforts, Wired couldn't even find my info on file.)