Telecom Tips give very cheap calls via your normal land line. Probably not
as cheap as Skype, but no fiddling with software involved, excellent
signal quality.

I can usually tell I’m being called on a cheapo VOIP line, as they’re
often half-duplex, so if you talk, the other guy can’t. Or have they

Another trick is if you pick up the receiver of a ringing phone, and say
‘hello’, and if you hear nothing but a slight hiss for half a second,
that’s your cue to say "I’m sorry, I don’t want any financial products"
and put the receiver down.

[The half second is the voice-recognition software kicking in]

Probably old-hat to USA folk, but starting to be more common in the UK. I’ve also had some auto-dialled ads. ‘Phone spam!