For the United Kingdom, I'd say having the Commonwealth of Nations (nations of the ex-British Empire which add upto 1.7 billion people) as their sphere of influence. Fifty-four nations (well fifty-three now that Zimbabwe has left due to their nutty leader Robert Mugabe, but will probably eventually return to the Commonwealth). And examples of British Commonwealth influence are very recent, like in 2000, when we intervened in Sierra Lione during the troubles there, and even Iraq and Kuwait, though not Commonwealth nations, are heavily influenced by the UK, and we, as has been proven by the two Gulf Wars, are still interestered in that region. Here is the Commonwealth list if this is of any use.
Countries of the Commonwealth of Nations
Antigua and Barbuda
Australia
The Bahamas
Bangladesh
Barbados
Belize
Botswana
Brunei Darussalam
Cameroon
Canada
Cyprus
Dominica
Fiji
The Gambia
Ghana
Grenada
Guyana
India
Jamaica
Kenya
Kiribati
Lesotho
Malawi
Malaysia
Maldives
Malta
Mauritius
Mozambique
Namibia
Nauru
New Zealand
Nigeria
Pakistan
Papua New Guinea
Saint Kitts and Nevis
Saint Lucia
Saint Vincent and the Grenadines
Samoa
Seychelles
Sierra Leone
Singapore
Solomon Islands
South Africa
Sri Lanka
Swaziland
Tanzania
Tonga
Trinidad and Tobago
Tuvalu
Uganda
United Kingdom
Vanuatu
Zambia
Zimbabwe
Other areas of British influence, i'd say, would be in the Carribean (still have West Indies Guardship for the Royal Navy) and the Persian Gulf / Middle East.