Traditionally, using arguments on the command line has been the best choice for bringing external input into scripts. But you have other input alternatives.
The For /F command in Windows NT and later lets you read in each line from an input file. For large numbers of items—say, 200 computers or 500 users—parsing an input file is a good choice. Also, you might create a script that uses an argument specifying the location of an input or output file, so the use of file parsing doesn't exclude the possibility of using an argument in a combined approach.
Another input option is menus. If the people who will use the script are unfamiliar with scripting, you can use static option menus to prompt them for text input. The Microsoft Windows NT Server 4.0 Resource Kit's Choice command and Windows 2000's Set /P command are the best alternatives.