What kind of smartphone and what OS does it run?
Do you sync with Outlook?
Some options include...
I have an iPod Touch (4th Gen) and sync with both Outlook 2010 and SkyDrive. I also use a 63-character random ASCII key (from GRC as you linked to) and transfer the code to my iPod Touch via an Outlook Note and iTunes. I can then simply copy-n-paste the new key into the wireless network properties on the iPod.
If you don't sync with Outlook then you could also use the SkyDrive app to sync a text file from a Windows or Mac computer and a iOS device, ie. iPad/iPhone/iPod Touch, or a Windows Phone. Create the new key, paste into a text file, sync with your mobile device, copy-n-paste the new key into the wireless network propterties then, and only then, make the change on your wireless router and other wireless clients.
I also use eWallet to store, in an encrypted database, system passwords, credit card info, etc. eWallet runs on Windows computers, Mac computers, iOS mobile devices and Android devices. I keep my network encryption keys in my eWallet database which I sync wirelessly between a Win 7 desktop, a Win 7 laptop and the iPod Touch. Like SkyDrive you simply need to save the new key in the eWallet database, sync your devices then change the key on the wireless router and other clients.
So you have options depending on what mobile device you have and want to use.
Personally I only change my home wireless networks once or twice a year depending on what I am doing, testing, etc and don't compromise security by using a shorter key.--
"When all else fails try what the Captain suggested before you started..."
MS-MVP Windows Desktop Experience