Best options:
• online donations: money via a PayPal link + bandwidth via mirrors
• subscription-donation hybrids
Other options:
• paid subscription
• Google AdSense
• sponsorship links
• trial subscription
• optimise your code
• premium content – pay for archives
• free content +only paid subscriber's content
• affiliate links
• organize focused events
• commissions on sales of reviewed (good or bad) products
• sponsored page
• banner ads
• sell something
• ebay auction
• newsletters: free and paid
The free version has tips and tricks; the paid version adds alerts, updates, downloadable reports and archives.
See also:
Boing Boing
Publishing: Free or Fee?
Paid Subscription Blogging, Part 1
Paid Subscription Blogging, Part 2