BBC radio often features a telephone number to respond to programmes or ask questions. Now, give them their due, they do have their social responsibility 'action line' 0800 044 044 which is free to call. But the main number they now use is an 0300 number. These are apparently public sector numbers which charge the same as a nationwide call - a call to an ordinary 01 or 02 number.
Now this is all very well, but increasingly people have phone packages with inclusive calls to 01 and 02 numbers. Such calls are absolutely free. Similarly, Skype users can have a package with free calls to all standard numbers. But calls to these 0300 numbers (and similarly to numbers beginning 0845, which charge a local rate) are not free on these inclusive calls. So just at the time many people are getting free calls, by using these 0300 and 0845 numbers, companies are ensuring that we still have to pay. Clever stuff, eh?
(Enthusiasts for BT ads will have noticed the telecom giant has recently made calls to 0845 numbers free - but I bet they still charge for 0300.)
Hot News - it seems from correspondence since posting this (see discussion in the comments) that 0300 numbers are free on Skype inclusive packages, and free on landline packages where calls to 01 and 02 numbers are free. On mobile phones and other packages with 'inclusive minutes', they are counted as inclusive minutes. So hurrah for 0300 numbers after all - but those using them could make this a bit clearer, as they usually say 'which are charged as a national call' or something similar.