Magesy

FLAC is the acronym for "Free Lossless Audio Codec". It's an audio-specefic file allowing lossless compression; Meaning the file size is compressed without any loss in the audio quality. It's similar to zipping, but FLAC gives you way better compression because it's designed specifically for audio files.
NOTE: Certain audio software like Soundbooth (as of cs5 anyway) or Audition 3.0 can't open FLAC files. If your audio software can't read an .FLAC file.... Then use the Audacity audio program to first open the file, and then export it as a WAV for use in your preferred audio program... Audacity is an open-source audio editor, it's able to read FLAC files and is freely availible to anyone.
http://audacity.sourceforge.net/about/
http://audacity.sourceforge.net/download/
The BBC Sound Effects Library is comprised of 60 cd's, Giving you a vast resource of diverse, royalty-free sounds recorded by the BBC's top engineers.

01 General Sound Effects
02 Exterior Atmospheres
03 Household
04 Interior Backgrounds
05 Transport Vehicles
06 Animals & Birds
07 Human Crowds, Children & Footsteps
08 MISC. Sounds
09 European Soundscpes
10 Communications Devices
11 Water
12 British Birds
13 Industry
14 London Taxis
15 Natural Atmospheres and rural soundscapes
16 Cars
17 Sport & Leisure
18 Explosions and guns going Bang!
19 Electronically Generated Sounds
20 Weather I
21 Weather II
22 Ships & Boats I
23 Ships & Boats II
24 America
25 Aircraft
26 China
27 Babies
28 Hospitals
29 Africa: The Human World
30 Africa: The Natural World
31 Equestrian Events
32 Greece
33 Adventure Sports
34 Livestock I
35 Livestock II
36 Farm Machinery
37 Horses I
38 Horses II & Dogs
39 Schools & Crowds
40 Spain
41 Trains
42 The Age of Steam
43 D.I.Y. and Building
44 Cats
45 "Dial 999"
46 Istanbul
47 British Birds II
48 Crowds
49 Suburbia
50 France - Paris
51 London
52 Exterior Atmospheres II: British Rural BG
53 India and Nepal: City Life
54 India, Pakistan and Nepal: Countryside
55 Footsteps I
56 Footsteps II
57 Urban South America
58 Rural South America
59 Hungary
60 The Czech Republic and Slovakia
...