It's been a while since the last rant, here are a few serious concerns for web developers to consider!
Resending POST data
The "back" button is very useful feature to have in web browsers. Unfortunately you can be prevented from going back to a page that is generated in response to filling in a form.
When you try to do this, the browser explains that the page can't be displayed without resubmitting the form data. This is since there are special rules which generally prevent an HTTP POST response from being cached.
So you can either resubmit the form, but you might not get the same results the next time around. There is no option of just seeing the original version of the page. The browser could ask you whether you wanted to see the old version, and could perhaps warn you that showing you the old version would be in defiance of web standards. This has to be an improvement over what is essentially a flat refusal to behave intuitively.
Web programmers can work around this problem, by making a web server respond to a web browser's posted form data appropriately. The solution is to instruct the web browser to be redirected to another web page, which can retrieved conventionally. This page you're redirected to appears in the browser's history instead, so your back button can work as normal.
For further technical details, I recommend reading the HTTP RFCs and the Wikipedia article on the "Post Redirect Get" pattern.
Click to close window
Many web pages, particularly those in popup windows have a hypertext link entitled "Click to close window". I feel this is redundant, since web browsers windows can be closed like any other. Given that web browsers open new "windows" as tabs, the wording itself isn't quite right either.
The only case for having such a link is for popup windows created in such a way to specifically hide the standard close window option. Even so this appears to be a case of trying invent a rounder wheel.
Print friendly version
When viewing websites like Google maps, it can be useful to make a hardcopy so you can review the information later. Unfortunately what you see on screen doesn't necessarily work so well on paper. This is what prompts web developers to create a "printer friendly" version.
While this seems like a great idea, I feel this is really just a sorry excuse that they couldn't figure out how to make a web page that appears correctly both on screen and on paper.
There exists a useful feature in CSS2, which lets you define formatting based on the "media" being used. You can use this to make your web page to look totally different when printed.
For an example of this in action, try using the "print preview" option in your browser when looking at my website. You should see immediately that the navigation menu disappears and background colours are turned off.
A useful article on this can be found on about.com