Show HN: Free Temporary Phone Number

I would like to pay for this. For example, reserve me a number for 5 days for 5 bucks. Is there already a service like this?

What technology do you use for something like this? And I agree with arb99 that this can be abused by spammers.

Expect to get used by spammers (for phone number verification for google/craigslist/etc)

Temp Phone Number? Can I use it to make international call?