As both Apple and Google introduce unwelcome changes in their phone OSes, here's a quick reminder that you do have alternatives to the Gruesome Twosome. The Keep Android Open campaign is gathering attention and support as the big red numbers on its page count down. The good news is that you do already have alternatives, and The Register has been reporting on them. But if you are not the sort of person who reads phone reviews, or writeups of alternative phone OSes, and just wants to buy a new handset and retain control of it and its contents, we thought it might be a good time to remind you of where to go and who to talk to. At the time of writing, the campaign says it's 123 days until Google's new measures preventing you from side-loading your own software will kick in. The campaign frames it in intentionally alarmist language: The Register has of course been covering both the looming Google changes as well as the campaign itself .…