I had a need to create 100s or even 1,000s of Magento products for debugging purposes. This tool creates X number of products "product 1", "product 2", etc.. for the SKU/name for Magento testing purposes. Actually it creates a CSV full of sample products for importing into Magento.
Call it on the command line as you would expect:
php create.php
It will write the output CSV to stdout, so feel free to pipe that to a file
php create.php > out.csv
You can then call Magento's import on that file to import the sample products into your Magento store.
You can specify the number of sample products to create
php create.php --number=100 > out.csv
It will use the default pricing/values from the seed.csv, except for SKU & name which are set to "skuN" and "product N" respectively, where N is an increasing number.
Magento's import/export is.... let's just say "less than desirable". I ran into bugs like categories not being assigned, and its slow as shit. There's a 3rd party tool which does a wonderful job - https://github.com/dweeves/magmi-git