Single post in PokéWalker Adjustments

I can confirm that you don't need a phone to use the Pokewalker - it can be opened in a PC browser just fine. The only caveat is that you won't be able to actually get steps by walking (unless you use a laptop or something, but I can imagine this being a bit inconvenient to use), but if you have watts for example you will be able to transfer those and use them to get Pokemon and items. The Pokewalker page (from where you can access the Pokewalker itself) is where you can trade in IPs for steps.