I am one of the developers for an app-in-progress called PhoneLeash (www.tinyurl.com/phoneleashfree
). Its on the market, free, but in very early stages, meaning we love interesting challenges like this!
As it stands now, PhoneLeash only forwards SMS (and missed calls) to an email address (SMS destination coming). You can also reply to SMS from the email account (if your device has an email-to-SMS address). I know PhoneLeash can forward to Heywire numbers (in < 5 hours!) since I've replied to texts from Heywire users, and no complaints.
Do Heywire numbers have an associated email? E.g. email@example.com
Why not just delete phone SMS store manually? Privacy? Laziness