With Labor Day weekend upon us, now is a good time to stock the virtual longbox with some digital comics. We reported the other day that Image has made 20 of its #1 issues free on comiXology; here's a roundup of some other free' n' cheap digital comics to check out over the holiday.

Centsless Books is a website that rounds up all the free Kindle books on Amazon, and it has a dedicated section for comics and graphic novels. There's a preview of Batman: Earth One up there, and a lot of first issues of different indy series. Some of the graphic novels aren't really — at least one book I checked was prose not a graphic novel, and Little Nemo's Wild Sleigh Ride is a picture book that uses Winsor McCay's illustrations (which are in the public domain). Well worth checking out, especially if you're a First Second fan, are the two Between the Panels books, which are promotional pieces put out by Macmillan, with creator essays, character sketches and side stories, all related to different First Second graphic novels. Aside from that, it's a pretty mixed bag, but one that looks like it will be fun to rummage around in. These Kindle comics will also work on the Kindle iPad and Android apps.

Infinity is a free iPad fanzine from Panel Nine, which has published Eddie Campbell's Dapper John and David Lloyd's Kickback as standalone iPad apps. The inaugural issue includes an interview with Lloyd, a preview of Dapper John, a roundup of digital-comics news, a couple of app reviews, art by Simon Russell, and an interview with PJ Holden, the creator of Murderdrome, a short comic that was booted from the iTunes store for being too violent (it's actually a spoof). It's a nice collection and well worth the effort of clicking that iTunes button.

Madefire, which launched in June, features free motion comics by various creators, including Watchmen artist Dave Gibbons.

Rob McMonigal has an enthusiastic review of Ryan Kelly's Funrama, the first issue of which is online for free.

If you are enjoying the new Valiant comics and are curious about their forebears, this is the weekend to satisfy your curiosity, as comiXology is having a 99-cent sale on the new and the old lines alike. It also has a 99-cent deal on Marvel's Siege comics.

Over at Dark Horse Digital, the Falling Skies comics are free and this weekend's 99-cent special is B.P.R.D.: Hell on Earth.

At The Beat, Todd Allen recommends Watson and Holmes, which is 99 cents and exclusive to Comics Plus.

Double Barrel, which features separate stories by Zander Cannon (Bone Sharps, Cowboys, and Thunder Lizards) and Kevin Cannon (Far Arden), is up to Issue 3, and that means the first two are 99 cents each.

Double Feature offers two comics by top creators for 99 cents; I bought and enjoyed its romance twofer, which featured J. Torres and Jamie S. Rich.

MonkeyBrain is another recently launched line that offers creator-owned comics for 99 cents or $1.99 per issue.

Artist Alley comics is yet another webstore offering comics for free or 99 cents.

And don't forget the great grandaddy of them all, SLG, whose Eyemelt Comics are always DRM-free and mostly priced at 99 cents.