Might as well use the cache — that’s what it’s there for. Like Vista’s Superfetch, or XP’s prefetch, or precompiling JSPs, or what have you.
For example, to load up your squid http proxy cache, just run:
wget -r -nd -H –delete-after http://your.portal.company.local/
or
wget -r -nd -H –delete-after -i some_file_with_URLs.html
wget’s –no-cache will force the proxy to download fresh copies, too. Try loading popular pages.