Here are some helpful kwikis for running or using Linux with digital camera equipment.

Be sure to also check the ArchLUG Kwiki page for kwikis that may be specific to your distribution of Linux.

http://www.cybercom.net/~dcoffin/dcraw/

Linux Software that is Digital Camera-friendly

LPhoto
XnView
IrFanView has been reported to work OK under WINE or Crossover Office

I would check out jhead [1] and exiftool [2]. Both can do comment/header/exif tag editing. jhead is limited to jpeg files, exif will work with most file formats that have some sort of EXIF tags in their header/meta-data.

jhead does a lot of nice things, but strangely I can't get it to display the text that Photoshop has put into some of these images.

That Photoshop stuff is called International Press Telecommunications Council (IPTC) information. Here's some stuff about it:

http://www.codeproject.com/bitmap/iptc.asp

ExifTool supports IPTC tags, and tons of meta information in images files. I'll let it speak for itself:

  ExifTool is a Perl module with an included command-line application that allows you to read and write meta information in image files.
It reads EXIF, GPS, IPTC, XMP, GeoTIFF, ICC Profile and Photoshop IRB meta information from JPG, JP2, TIFF, GIF, CRW, THM, CR2, MRW, NEF,
PEF, ORF and DNG images.   ExifTool also extracts information from the maker notes of many digital cameras by various manufacturers
including Canon, Casio, FujiFilm, Minolta/Konica-Minolta, Nikon, Olympus/Epson, Panasonic/Leica, Pentax/Asahi, Sanyo and Sigma/Foveon.

I use it to pull meta information out of canon CRW files on occasion, and it dumps the IPTC tags just fine.

Here are some fun things to do ...

Google-A-Webcam

Use the following Google queries to return hundreds of unsecured webcams (mostly security cams):

inurl:" ViewerFrame?Mode="
inurl:" MultiCameraFrame?Mode="
inurl:"view/index.shtml"
inurl:"axis-cgi/mjpg"

DigitalCameraKwikis

Here are some fun things to do ...

Google-A-Webcam