How to make animated gifs?

I just learned an easy way to create animated gif pictures:
Tool: GIMP ( GNU Image Manipulation Program)
Step1:
Prepare several pictures as the frames, e.g. p1.png, p2,png.
Step 2:
File->Open->"p1.png"
Step 3:
File->Open as Layers->"p2.png"
Step 4:
Image->Mode->Indexed
Step 5:
Save as->"test.gif"->Save as Animation->Export->
Adjust the parameters, for example
"loop forever"
"Frame disposal where unspecifed: One frame per layer (replace)"

Upcoming Conferences in Transportation Field

1. the Hong Kong Society for Transportation Studies: http://home.netvigator.com/~hksts/call.htm
2. Conference List in Kevin's website: http://redvillage.homelinux.net/index.php?Page=conference
   

GIS Data

VA:
http://www.virginiaplaces.org/boundaries/gisdata.html
http://gisdata.virginia.gov/Portal/

MD:
http://www.marylandgis.net/SHAdata/

MA:
http://www.mass.gov/mgis/laylist.htm

Other regions:
http://seamless.usgs.gov/
http://arcdata.esri.com/data/tiger2000/tiger_download.cfm
http://data.geocomm.com/catalog/index.html
http://www.nationalatlas.gov/atlasftp.html
http://gisdata.virginia.gov/Portal/

Scripts for ESRI software:
http://arcscripts.esri.com/

Freeware (Forestry GIS)
http://www.forestpal.com/fgis.html

Where to find traffic data in Maryland

1. CATT Lab
Traffic Data Extraction Software (Web Based)
http://www.cattlab.umd.edu/index.php?page=research&a=00005

2. MD SHA
Internet Traffic Monitoring System (I-TMS)
http://shagbhisdadt.mdot.state.md.us/TMS_Reports_Site_RedirectPage/

3. MD SHA
GIS File Download Center
http://www.marylandgis.net/SHAdata/