WordPress is turning out to be really annoying in the amount you cannot do without installing yet-another-plugin™. I understand why they pick some of the defaults they do, but to not give any ready way to adjust them is … irritating.
So, to increase the maximum file size of an upload, and also the maximum size of a post, for me, the quickest and easiest way without installing a plugin, or editing the wordpress source (that may get overwritten on a patch), is to add two lines to the
.htaccess file in the root of the wordpress installation:
php_value upload_max_filesize 64M php_value post_max_size 64M
Make sure you put them outside the BEGIN and END block.