Ask HN: Non-cellphone long distance

After my first month as a web entrepreneur, it has become painfully clear that I need to talk on the phone long-distance without cell-phone glitches. I live at the top of Potrero Hill in SF, and the cellphone reception here is horrible (I've gone through two carriers).

I'm moving in two months, so I'm not keen on buying a landline unless I really have to. I've tried Skype on and off for years. Skype is a disaster, far glitchier than cellphones, just not workable for business talk and project talk.

What service do you use for talking long-distance? Or is spending the $$$ on a landline my only real option?