For months, I’ve been using Wordcycler (Windows, freeware) to manually sync individual items from Instapaper to my Kindle 3G + Wi-Fi via USB cable. Now that I have a smaller number of articles to read, I’m going to try receiving new items via Wi-Fi through Instapaper.
I’ll also start trying Instapaper’s Send to Kindle bookmarklet for immediate delivery (Account > Manage My Kindle Settings).
If this works well, it’ll be fantastic not having to connect my Kindle to my computer every few days. I’d only need to worry about charging it.