The new forum software has a couple features that I thought I'd bring to everybody's attention.
First of all, if you're on a slow (or data-capped) internet connection, you can turn off display of images. To get to this setting, go to the upper right corner of the forum page when you're logged in, and click on "Settings". Scroll down the menu bar on the left until you see "My Settings", then under that, "My Account" and under that "General Settings". Click on General Settings. You can also go there by clicking "Forum Actions">"General Settings" in the top menu bar of the forum page.
Then, scroll down to "Thread Display Options". You can turn off "Show Images" for images that people post, and you might also want to turn off avatars and signatures if you're really on a slow connection. Turning off the images will make them available as links, so you can still see them by loading them individually, but they won't all load at once and slow down page loading.
While you're there, look at the bottom of that section and you'll see "Default Thread Age Cut-Off". If you're wondering where all the older threads went, you can change this option to "Show all threads" to see everything. Or, if you're on a slower connection, limiting the number of threads it displays may speed up access somewhat.
For slower internet or older browsers, or if you just don't like running scripts, scroll all the way down to the bottom of that page to "Miscellaneous Options". Select "Basic Editor" and "Enhanced Attachment Uploading Off". This will give you an interface similar to the phpBB interface on the old forums instead of the slower advanced interfaces. If you aren't extremely limited, go ahead and turn these advanced options on if you want them.
Since users with slow internet can turn images off, and since large images no longer break the page on the new software, I suggest relaxing the previous image size and quantity restrictions. It's still not a good idea to go image-crazy and make a thread that's going to take forever for anybody to load, but I think we can at least increase the limit. I'd like to hear back from people with slower internet about this, especially because I've heard vBulletin can be resource-intensive in general. I'm hopeful that the suggestions I listed above will improve the experience dramatically for people with 56k or similar.
On that note, Lionel says that we have plenty of server space, so I'd encourage people to upload images as attachments. This prevents the "link rot" that often occurs with old links from photo hosting sites.