I was in a bar the other day when everyone reached for their mobile phone. I mean everyone. OK, the pub wasn’t that packed, but there must have been a dozen or so people sitting around chatting over a pint of beer or glass of wine before the gentle hum of conversation was shattered by a shrill ring.

The reason everyone stuck their hand in their coat/trouser pocket or handbag was that we all shared the same ringtone. It’s known as “Old Phone”, at least it is on my Apple iPhone. It sounds like the bell-like ring of – you guessed it – an old phone. It’s a bit like one you’d hear going off in an old Sweeney or Likely Lads episode.

Why did we all choose this tone? I didn’t ask my fellow drinkers but it seems pretty obvious that this is the least bad of a terrible choice of mobile ringtones. Unless you’re 15 years old the classic ring of an old analogue phone sounds boring enough not to have everyone else around you either sneer or burst out laughing.

Here are some other iPhone ringtone names: Duck, Motorcycle, Pinball, Sci-Fi, and Xylophone. All sound ridiculous.

And the iPhone is pretty conservative when it comes to its ringtone options. And don’t get me started on all those theme-tune ringtones that were so popular a few years ago.

There is surely a market for purely subtle, un-alarming ringtones. No alien squawks, parrot parodies, Britney Spears Ambulance calls, madmen raving, or space-car cowhorns – just a reasonable selection of decent little noises that won’t offend anyone.

New research from IDC forecasts that the number of worldwide wireless subscribers and customers will grow by a little more than a billion over the next four years, generating $800 billion in global wireless service revenue by 2011.

Mobile entertainment will account for 5.1% of this total revenue and 23% of all mobile data revenue.

Shockingly, the vast majority of this mobile entertainment revenue will be derived from ringtones and ringback tones. (What is a ringback tone? It’s when people call you, and instead of a ring they hear music.)

According to IDC, ringback tones will overtake even ringtones in 2010 and become the single largest revenue source for mobile entertainment.

Here are the top 10 ringback tones for US Verizon users:

1. I'm Me - Lil Wayne

2. With You - Chris Brown

3. Love In This Club - Usher featuring Young Jeezy

4. Independent - Webbie

5. Low - Flo Rida

6. Suffocate - J. Holiday

7. Superstar - Lupe Fiasco

8. Sorry - Buckcherry

9. No Air duet with Chris Brown - Jordin Sparks ft. Chris Brown

10. Take You There - Sean Kingston

Ever heard of them? I’m afraid that we all will soon…