phpBB 3.1 codenamed Ascraeus has already seen a number of improvements to the process of uploading attachments. We have recently updated the plupload library introduced as part of a GSoC project in the summer of 2012 to version 2.0. I want to use this as an opportunity to present new functionality relating to attachments introduced in Ascraeus.
Firstly it is now more easily possible to upload multiple files at the same time. You can even drag and drop files into the upload area directly. Uploaded file size limits are no longer as limited as before and there is visual feedback throughout the uploads making use of new HTML5 features. So you can watch the upload progress as you continue to edit your post.
Further we now offer an option to download all attachments contained in a topic as an archive file (zip, bz2, gz, tar). This feature has been integrated into a new topic toolbox which contains topic options such as subscription management and bookmarks.
Recent user interface improvements also included changing the topic title link to point directly to the oldest unread post of a topic instead of the first post. Previously you had to be aware of the purpose of the small yellow icon next to topic titles to get there.
Just before the Alpha2 release we fixed bug PHPBB3-11525 which resulted in users having their avatars set to seemingly random avatars of other users. This happened to a few users on Area51, so you may want to check your avatar on Area51 and correct it if it was modified.