All of the magazines that I'll review here (Analog, Asimov's, Baen's, F&SF, and Interzone) are available in eBook editions. They're also available in a wide variety of formats. It is beyond easy to pick any of them up, with or without a subscription.
I read all of these on my eBook device: the orginal eBook. I've been using it for more than two years now, and I love it. It's much cheaper than either Sony's eReader or Amazon's Kindle. It may be backlighted, but the battery lasts more than twenty hours, takes less than two to recharge, I can highlight passages, search for notes or text, take notes on it, bookmark, and I've never been able to fill up more than 60% of its memory. I take it everywhere. I particularly like downloading text files from Project Gutenberg, uploading them to the eBook, and reading them there. It supports the file formats: plain text (.txt), rich text format (.rtf), Microsoft Word documents (.doc), HTML (.htm or .html), and Rocket eBook Editions (.rb).
However, even if you don't have a dedicated eBook reader, you can still enjoy electronic copies of all these magazines:
Baen's Universe They publish six issues a year. $30 for a year's subscription, $6 for an individual issue. They're available in: Mobipocket, (palm/blackberry/symbion,etc.) (.prc); RTF, PDF, Microsoft Reader (.lit), Rocket E-Book (.reb), HTML (as a .zip file).
The other four are all available from FictionWise. Analog is $4/issue or $33 for a year; same for Asimov's; F&SF runs $4.50/issue or $37 subscription; and Interzone is $5/issue and $24 subscription (they publish 6 issues a year). And they just keep adding more formats; generally they're available for Kindle, Palm pilots, Sony eReader, PDF, Microsoft Reader, eBook, Franklin eBookMan, iSilo, Mobipocket and hiebook (whatever that last one is).
I understand all the objections to eBooks, and lord only knows I haven't given up physical books. Wider selection, ease of reading in the tub, etc. However, especially for the fiction digests, you may want to give it a chance. Reading them electronically, you never have to worry about finding them, or having them stack up on a shelf somewhere. You're supporting the markets that bring us the short fiction that keeps the field vital, and reading short fiction from a screen is easier on the eyes than reading a whole novel (although I have no problem reading long novels from any kind of screen now).
So this is my Earth Day post pimping my all-time favorite tech toy, my beloved eBook. I hope that this will give folks out there some food for thought and some specific resources if they want to dip their toes into the electronic fiction market.