Long link or redirect?

Should I ask for links to a redirect URL or the full URL?

For example, should I ask other sites to link to:
www.mysite.com/shortlink (which will redirect to the link below)

or should I ask for a link to the full/normal/long URL?
www.mysite.com/directory/pages/default.aspx

In my website I'm using the redirects already..

So long as you are using seo friendly URLs I would say the long URL is the better of the two, there is less ambiguity that way.

What sort of redirects are you using? Are we talking a simple URL rewrite, or something more exotic?

They're just normal 301 redirects. No URL-rewriting. They are redirecting to the long URL. So you click on a short URL but you end op on the long URL :-)

I would avoid that as much as possible, generally there is nothing wrong with 301 redirects, but save them for when it's strictly necessary especially if you're stuck using IIS (which I assume you are). There is no real benefit to your users shortening the URLs, and it may make your site harder to crawl or look odd to the search engines, which is always to be avoided.

I take it your long URLs are otherwise neat and friendly?

I'm using redirects in the site because that way the internal links are easier to maintain. When a link changes I only have to change the redirect instead of changes the links through the whole site. A decent CMS would do that job, but mine is too expensive and can't do easy things like that.

So now I was thinking, should I use these redirects in my Link Building as well or should I use the long URL's.

The long URL's are really long but in most cases they have the necessary keywords in the URL.

But I thought that shorter was better anyway. So why not use the short URL's?

Well if the long URLs are prone to change they shouldn't be used in linkbuilding because you will be constantly losing links.

That said I think the system you are using could end up causing you loads of problems, if you are redirecting from a small link to a long link (I am assuming that the long link ultimately ends up in the address bar when you are on that page) you could run the risk of duplicate content if the page was once elsewhere (there are a variety of other problems if this is the case, this is just the first I could think of).

Short urls aren't necessarily better, if your long url is something like: ratemywidget.com/round/blue-widgets/best-widgets.php that's no problem at all, it actually gives the search engines some valuable information. If on the other hand they are huge and have a lot of random other data in them some sort of rewriting would be good a good idea.

I would build links to the actual URL, not the redirect/short URL. By linking to the short URL, you are counting on the search engines to properly follow your redirect and crossing your fingers that the juice gets passed along through the redirect. Remember, the search engines spiders are automated, not human. If something happens with your 301, you now lose any backlinking benefits to said link. Pointing a backlink to the actual link will make sure the proper credit gets assigned and any visitors land on the correct page.