Code Golf: 1x1 black pixel

Answer 1

DrRacket: 23 chars

#lang slideshow
(disk 1)

Answer 2

WBMP, 5 bytes:

00 00 01 01 00

Can't imagine anything smaller

Answer 3

<div style="height: 0; width: 1px; border-top: 1px solid #000">

But positioning it will take more.

Answer 4

Python+PIL 68 chars

from PIL import Image
Image.fromstring("P",(1,1),"\0").save("B.gif")

Answer 5

An old image format I used to use: 4 bytes

 01 00 00 0C

The format consists of an array of 16 bit integers (little endian):

Bit mapping:

0-10:  number of pixels to shade
10-11: control bits
12-15: VGA16 pidel color

Control bits values:

0: normal
1: end of line
3: end of file