Below are download links to the various firmware ipsw files for iPhone and iPod touch devices.

1st Generation iPhone
iPhone (1.0.1/1C25)
iPhone (1.0.2/1C28)
iPhone (1.0/1A543a)
iPhone (1.1.1/3A109a)
iPhone (1.1.2/3B48b)
iPhone (1.1.3/4A93)
iPhone (1.1.4/4A102)
iPhone (2.0.1/5B108)
iPhone (2.0.2/5C1)
iPhone (2.0/5A347)
iPhone (2.1/5F136)
iPhone (2.2.1/5H11)
iPhone (2.2/5G77)
iPhone (3.0/7A341)
iPhone (3.1/1_3.1_7C144 241 MB)

iPhone 3G
iPhone 3G (2.0.1/5B108)
iPhone 3G (2.0.2/5C1)
iPhone 3G (2.0/5A347)
iPhone 3G (2.1/5F136)
iPhone 3G (2.2.1/5H11)
iPhone 3G (2.2/5G77)
iPhone 3G (3.0/7A341)
iPhone 3G (3.1/2_3.1_7C144 242 MB)

iPhone 3GS
iPhone 3G S (3.0/7A341)
iPhone 3GS (3.1/2,1_3.1_7C144 306 MB)

1st Generation iPod touch
iPod touch 1G (1.1.1/3A110a)
iPod touch 1G (1.1.2/3B48b)
iPod touch 1G (1.1.3/4A93)
iPod touch 1G (1.1.4/4A102)
iPod touch 1G (1.1.5/4B1)
iPod touch 1G (1.1/3A101a)
iPod touch 1G (2.0.1/5B108)
iPod touch 1G (2.0.2/5C1)
iPod touch 1G (2.0/5A347)
iPod touch 1G (2.1/5F137)
iPod touch 1G (2.2.1/5H11)
iPod touch 1G (3.0/7A341)

iPod Touch 2G
iPod touch 2G (2.1.1/5F138)
iPod touch 2G (2.2.1/5H11a)
iPod touch 2G (2.2/5G77a)
iPod touch 2G (3.0/7A341)