Sometimes it seems webmasters are reluctant to link to other sites. They are concerned about leaking PageRank or taking visitors away from their site. Thing is I really think this kind of defeats the point of hypertext links and the Internet in general. It's got to make your site more useful to your visitors if you've got some quality outbound links to authority sites.

If you're asking about "Authority" sites, then it's probably best I refer you to the Hilltop algorithm - which I'll try and explain briefly here. The Hilltop algorithm is nothing new and has been around since about 1999. It uses "Expert" sites which contain quality info about a topic plus a few good quality links to non-affiliated "Authority" sites. Non-affiliated tends to mean sites that are not within the same class C IP address range.

Here's a diagram I just drew in Paint so excuse the rough edges. The green ones are the "Expert" sites and the blue ones are the "Authority" sites. The lines are one way links from "Expert" to "Authority" sites. The top "Authority" site is doing slightly better as it has more links and some of its links are from sites that link to other "Authority" sites...

So what I'm trying to say is - "Go Ahead!" Link to external sites - at the very least it means your website is useful to you and you'll never forget where your favourites are!