pdftk doesn't rotate pdfs

pdftk - A handy tool for manipulating PDF

Highly recommended: I use it for concatenating pdf documents, or selecting a subset of pages. I get it via fink, but you can also find it online. Unfortunately, pdftk doesn't allow you to rotate pages.

Preview.app lets you rotate and save pdfs: ⌘-L, ⌘-R, or use the menu—to rotate a single page, hold the option (alt) key while doing this.

LATEX Equation Editor

In an earlier post I mentioned L^AT_EXiT, by Pierre Chatelier. The L^AT_EX Equation Editor is similar in function—and not entirely dissimilar in appearance.
I'm not sure yet which I prefer. Both are free—try both. If you already downloaded L^AT_EXiT last year, make sure you try the latest version.
If you have a Fink tetex installation, you must set the preferences for L^AT_EX Equation Editor to specify that L^AT_EX is in /sw/bin/ and ghostscript in /sw/share.
See also mimetex and L^AT_EX render.

LATEX iT

\pi^2 =&6\sum_{i=0}^{\infty}\frac{1}{i^2}\\
\pi^4 =&90\sum_{j=0}^{\infty}\frac{1}{j^4}\\
\pi^6 =&960\sum_{k=0}^{\infty}\frac{1}{k^6}

This small app from Pierre Chatelier allows you to create JPG and PDF images for inclusion in your web pages, easily from L^AT_EX math. Here you see a jpg — click the image to see the pdf.

When you generate a pdf file, L^AT_EX iT embeds the L^AT_EX source in the pdf, so that,later, you can paste the pdf back into this application, and edit the source. Brilliant!