If you have no SO to worry about and don't want to have a second phone, don't bother getting one.  I have only my one cell phone number and I use it for hobbying.  Maybe not the smartest thing to do, but I have no GF or wife, or any kind of SO to worry about.  Been doing this for going on 7 years, no probs with LE so far.  Even with a hobby phone, there is always risk involved in what we are doing here.

Bottom line is, if you're busted, you're busted, hobby phone or no.  If a SO should happen to come into your life, I would def get a hobby phone.  I would do that if that happened to me.

I'm self-employed and not married or cheating on anyone. So far, my dealings with providers have been thankfully free of unhinged harassment or shakedowns, but it's nice to know that if my lucky streak ends, I can cut all ties by simply tossing my phone in the trash.

If I had been using my regular phone in order to save a few bucks, my full identity would always be at their mercy, and I would have less peace of mind. And, yes, LE is a consideration. If you've been paying attention to the news, you know that the trend has been towards less personal privacy much greater police and corporate power in areas like electronic devices. Who knows what regrets we'll have tomorrow for simple precautions not taken today?

That way when they call you back, they don't have to worry about your wife or child answering.

Unless you are single like I am then don't fool around with this one.  Divorce is more expensive and messier than any fine or legal expense.

I've been using my Google Voice phone number with dancers for a while. It's free and I can pick my own phone number.  I can check messages on my regular smartphone and immediately wipe the browsing history.  I don't have calls or texts forwarded to an actual phone so it's more like an Internet voice mailbox. But I can forward calls and text notifications to my phone and the incoming number shows up as Google Voice and not the actual caller's number.

Even if you're single it's a good idea to keep your hobby life somewhat separate from your regular life for a couple of reasons:

1.  As another use mentioned, you don't want some crazy provider to have access to the "real" you.
2.  Even if you don't have a S/O now it's likely that you'll have one at some point in the future and having a separate line already established will make things a lot easier.

If you do get a hobby phone I suggest the tracfone.  You can get one for as low as $9.98 at Wal-Mart.  That's what I use and that's what I've seen most other hobbyists suggest when the topic comes up.  Also, when you get it make sure to activate it from a pay phone instead of your home phone or cell phone.

buy with cash.  Don't bother with filling out a bio.  Don't link to a web address, even a private free one.  It's not required.   The hardest part is charging it occasionally though my new tracfone only gets charged every few months.  
Turn the hobby phone off when not in use.  I prefer to delete the call log after use.  Better to be suspected than give the ammunition to prove the allegation.
Guys have to learn to work absences into their schedules with some legit activity...  flexibilty in your pocket cash...  and a hiding place that works for you.  Like the guy who hid his hobby phone in a "junk drawer" in his desk with all old phones, chargers, headphones & mp3s.  I've heard of spare tire space or other trunk hide out (not in a shared car), a work shed out back, drawer in office at work, gym bag or locker, tool bag on bike.  

It is easier to keep the dual life separate if you are single but still needs to be kept private.  
H