Garmin 560C Memorey

I don't know the amount of memory you have, but you can delete any/all of the voices you don't use to free space. If you need them later you can download them with the WebUpdater.

Glad you filled the profile out.

The C550 has plenty of internal memory for your custom poi's. Probably into the tens of thousands, depending on size. Also depends if you load mp3's to internal memory you will reduce the space for poi's. You can use a SD card as well. They are fairly inexpensive. You can if you desire delete any voices you won't need.
I would strongly suggest you copy your files to your computer before you delete anything.

sorry my mistake a meant 550C

I just added a whole bunch that I downloaded from this site. Altogether, there were 10,098 POIs and the POI file is 1.12 MB (1,179,648 bytes). That's about 117 bytes/POI on average, although it will depend on how descriptive they are. This is on a Nuvi 350, but should be similar for most GPSr.

May be someone who has downloaded all 1,000,000 POIs from this site could check their POI file

Something else you can check, after connecting your c550, it will be listed as a drive. You can check the available space by going to "my computer" > garmin device, then right clicking and then click on properties. This will show you a pie chart with the space used and available.

hope the info helps