LED Numbers and Letters
Golfscript, 142 137 chars

Unfortunately some of the characters are control codes, so I'm going to have to post a hexdump and a link rather than a direct copy of the source:

00000000  27 2b 27 3a 28 27 2d 27  36 35 2a 3a 5e 28 6e 27  |'+':('-'65*:^(n'|
00000010  7c 27 3a 29 27 20 27 3a  7c 36 34 2a 3a 40 27 20  ||':)' ':|64*:@' |
00000020  7c 0a 7c 20 27 3a 76 5b  27 77 12 5d 5b 3a 6b 6f  ||.| ':v['w.][:ko|
00000030  52 7f 7b 7e 2f 65 1f 6d  6c 27 7b 7d 2f 5d 3a 24  |R.{~/e.ml'{}/]:$|
00000040  2c 2c 7b 3a 78 3b 5b 27  60 40 50 20 00 10 2c 08  |,,{:x;['`@P ..,.|
00000050  1a 04 00 02 05 01 03 27  7b 7d 2f 5d 7b 24 78 3d  |.......'{}/]{$x=|
00000060  26 21 5b 34 38 78 2e 31  30 2f 37 2a 2b 2b 5d 7c  |&amp;![48x.10/7*++]||
00000070  2b 3d 7d 25 33 2f 7d 25  7a 69 70 7b 7c 2a 7d 25  |+=}%3/}%zip{|*}%|
00000080  76 2a 76 40 29 6e 28 5e  28                       |v*v@)n(^(|


leds.gs

Note that all of the characters are 7-bit values and legal Unicode code points, so the number of characters is the same as the number of bytes in UTF-8.

Basically there are two hard-coded arrays. The first is a 15-element bitmap indicating which of the 7 segments control each grid cell. The second is the 7-segment encoding of the 16 characters. Then it's just a case of using bitwise and to work out which segments are turned on and doing some string manipulation.