Here are a few programs I can not do without. They're free, and make being a webmaster much easier.
A cgi script that allows you to run commands on your server, even if your web host will not give you telnet access. Also good for getting files created by other scripts that are owned by user 'nobody', instead of your username. Ever tried deleting them? Well, now you can.
AXS Visitor Tracking System http://www.xav.com/
A very fine hit counter. Fairly simple to set up, if you use footer files on your site. Gives detailed information. Much better than the stats software that came with your web-hosting account.
A Perl text replacer script. Handy if you're not familiar with Unix commands. Make siteways changes in seconds. The original author's site does not list it any more. Can still be found via a search engine (hint, hint).
FTP Explorer http://www.ftpx.com
The charm of this software is that it looks a lot like the Windows shell, and that makes FTP'ing a little less intimidating for the novice webmaster.
Putty Telnet / SSH Client http://www.chiark.greenend.org.uk/~sgtatham/putty/
A simple-looking, but sophisticated, freeware telnet and SSH client. Can be run from a floppy disk. Useful for the mobile webmaster.
Email Remover 2.4
Not currently available from the author's website, but can be found by Googling for a file named 'eremov24.zip'. This is an email account checker. It can be run from a floppy disk and can check multiple email accounts. Allows you to highlight spam and delete it, and download emails if need be. WARNING: It has a bug. Do not change the order of the emails in the software window before deleting; you'll end up deleting the wrong ones.
RFTP 32 Version 0.99
Again, not currently available from the author's website. This is a self-contained FTP client that can be, you guessed it, run from a floppy disk. Search around for a file named 'rftp.exe'.
If you do not see a pattern emerging, then let me elucidate: the last three programs can all be run from the same floppy disk. You can leave your laptop at home, and work on your site from internet cafes.
The only thing left would be a WYSIWYG HTML editor that you can run from a floppy disk; that would be asking for a lot. However, the Mambo content management system http://mamboserver.com comes with one pre-installed. There's also a WYSIWYG plugin for the blog software http://wordpress.org/ .
Either is a useful addition to any website. You can keep it updated while on the road.