wget -q http://www.whatever.com/filename.txt -O /path/filename.txt 

-q is quiet mode so you can throw it in a cron without any output from the command


This option works

wget -N http://server/folder/file1.html

info

-N,  --timestamping            don't re-retrieve files unless newer than
                               local.

Use curl instead?

curl http://server/folder/file1.html > file1.html