Since the previous edition of snippets focused on math, we'll focus on memory in this one.

• Back in 2008, I reviewed a flashcard program for the Mac called Mental Case. It's been through several upgrades and adaptations since then, including the addition of an iPhone/iPod Touch version and an iPad version, which have now been combined into a universal app called Mental Case Flashcards HD (iTunes Link).

Before the end of summer 2011, they're preparing to upgrade the Mac version to 2.0 followed shortly by both iOS versions. The 2.0 version will only be available via the new Mac App Store. Unfortunately, the only way for current owners to migrate is to purchase the current version at some point on the App Store. To help ease this transition for current owners, Mental Case at the Mac App Store will be half price ($14.99) until January 18, 2011.

On a semi-related side note, AppShopper has announced it will be adding Mac App Store support soon.

• Looking for something to memorize with Mental Case? How about the periodic table of the elements? Some do this by memorizing Tom Lehrer's Elements Song, but it's often criticized for not being in numerical order. In response, there's now a version with the elements sung in order, to the tune of Billy Joel's We Didn't Start The Fire.

Alternatively, there's the acrostic mnemonic approach. By remembering a few sentences taught in this video, you'll have all the elements memorized quicker than you might expect!

• The Phonetic Peg Memory System is another great way to memorize things. Encouraged by the recent Magic Café thread on free Phonetic Peg Memory System resources, I went looking for more.

Since first coming across that thread, I've discovered PinFruit, a number-to-mnemonic converter like Rememberg and the Phonetic Mnemonic Major Memory System Keyword Database. I also ran across the Number Thesaurus for the first time, which reasonably settles what the Major/Peg System should be properly called.

When looking for mnemonic for a given number, I recommend trying it in all 4 of these sites, as you'll get a more complete picture of the possibilities. All of these new resources have been added to the Memory Tools page.

• I'll round out this edition of snippets with some fun challenges. First, there's cow-pi.com, where you can sign up to pit your knowledge and recall of Pi digits against others online! There's even a practice mode if you're not sure of your abilities yet.

If words are more your thing, mental_floss blogger Sandy Wood often features puzzles known as word ladders or doublets. At this writing, the most recent one asks you to go from BOOK to FILM.

If you find these word ladder puzzles challenging, the Wolfram Alpha search engine can help. Using the BOOK to FILM puzzle linked above, we need to find out what words are one letter away from the word BOOK. We start by entering the word _OOK in Wolfram Alpha (note the underscore in place of the missing letter), which then lists the words that it could be. For a more complete picture, we also search for B_OK, BO_K, and BOO_. From there, you can decide which words will take you closer to FILM. This is a nice tool, and doesn't ruin things by solving the puzzle for you.