Readers Suggest Cool Mapping Tips

Plotting to Impress... Last week's Dispatch, Maps, Aerial Images and Yellow Pages (May 26), generated some amazing e-mails. Want to plot ocean views in California? Crimes in Chicago? Taxi cabs in Houston? It's all below.

Neil Lefmann at N.A. Lefmann Associates in Campbell, CA, raves about Google Earth (formerly Keyhole). "The best feature of the program is the ability to overlay other files onto the aerial map and to control their transparency. I have successfully used this feature in a formal arbitration hearing involving mountainous lands in Santa Clara County to demonstrate the topography and boundaries of the subject and comparable sales.

"I created an overlay land sales map using a USGS topo map and overlay files of assessor's plat maps showing parcel boundaries. Getting the overlays properly positioned on the aerials manually takes some time, but 'flying' the areas on the maps while projecting the images onto a screen gives a real 'wow' factor that I believe was a deciding factor in my success in the arbitration.

"BTW, in that same arbitration, the presence or absence of Monterey Bay views was also at issue, and I was able to demonstrate the view from any point by using a feature of the program."

Bill Miller at Appraisal Research Counselors in Chicago writes, "Some of the best mapping applications at the moment are done by freelancers... Paul Rademacher has mapped for-sale housing and rental apartments from Craigslist at HousingMaps. Adrian Holovaty has created an almost real time Google map of Chicago crime data at ChicagoCrime.org. Need to find a taxi? Use Google Ride Finder."

Instructions -- Apartments ... Go to HousingMaps. Click the Chicago bubble or the City drop-down menu. You'll generate a map of Chicago populated with balloons (yellow=pictures, red=no pictures). Zoom into the actual property from the map or an aerial image (for images click the "Satellite" link above the map), using the scale to the left.

-- Crime... Go to ChicagoCrime.org. Filter for crimes by location (e.g., barbershop, bowling alley), type (arson, bribery), district (address), time of day and date.

-- Taxis ... Go to Google Ride Finder. Click the name of a City, say Houston, TX, to display of the exact location of hundreds of cabs. Click the nearest balloon to call one of the three companies.

--Peter Pike