A pilot wants me to supply data to load into Memory Map on her IPad. Are .QCT files the only option? If so, how can I create .QCT files from a set of x and y coordinates? I normally use ESRI's ArcGis to generate Shape files for my other GIS applications. Any advice would be very welcome!

Use gpx, Memory Map will treat the data as a route or track. Qct is for maps.

My data isn't really a root or track. It is merely a set of co-ordinates which show where certain crops are, and I want them to be displayed as a set of dots or crosses on the map. So is gpx really the correct format? And if so how can I create a suitable file from a spreadsheet or CSV file?

Gpx is the only format that the iPad app will read, in this case MM will treat the file as a list of waypoints. The desktop version of MM can import a csv or ESRI file & export as a gpx file. Alternatively, use GPS Visualizer to convert a csv to gpx.

This is the format for a CSV file.

WP04,Lat,Lon,Symbol,Name,Comment,File,Radius,Display,Unique,Visible,Locked,Category,Circle

Lat & Lon are in decimal degrees, on the WGS84 datum, N and E are positive, S and W are negative.

Symbol is an integer indicating the symbol type. Experiment with exporting some samples to get the values. -1 means use the icon of the linked file.

Name is the text name, which may be shown on the map (use quotes if the name contains a comma)

Comment is the comment shown in the properties, in escaped form to allow line-breaks

File is the full path of the linked HotSpot filename

Radius is the alarm/circle radius in meters. Enter 0 for no circle.

Display is an integer that controls the "Show label" flag. A value of 1 does not show the name, a value of 0 does. (The logic got inverted, somehow)

Unique is the unique name used when programming a GPS. Each waypoint must have a different unique name. No punctuation, etc, allowed. This may be left empty.

Visible is 1 to show the mark, 0 to hide it

Locked is 1 to lock the mark, 0 to unlock it.

Category is the category for the mark. Objects are organized by category in the Overlay Properties dialog, and you can hide or show all marks in a particular category using the Overlay -> Show All / Hide All menu commands.

Circle is the circle or alarm type:
0 - no circle, 1 - passive circle (no alarm), 2 - Proximity alarm, 3 - Anchor alarm