DSO is a freeware astronomical program for Palm OS devices that should help to plan observations of deep sky objects. The program allows to search for objects in the NGC/IC database by the object:

• Minimum dimension
• Availability (i.e. its altitude at the particular time and location should be above some minimum)
• Type (galaxy, globular cluster, nebula etc.)
• Visibility (log(C0/C)) in particular telescope according to the visibility concept developed by Jose Torres or maximum magnitude

You could also limit search to Messier, Caldwell or Hershell 400 objects. Features

Performs search of NGC/IC objects to be observed

Performs search of closeby NGC/IC objects in the vicinity of a specified one

Exports search results directly to Planetarium

Calculates visibility for any object and graph the result

Creates an observation plan

Locates the object for equatorial mounts in 'manual go to' style by calculating the number of turns of RA and DEC handles from some star or other DSO

Views other people observation logs (in Russian, from www.astronomy.ru)