Sticky notes are great, but sticky notes that can have reminder alarms, be sent to other Macs via Bonjour, sent over the web and SMS, archived and more - are better. If any of these features have your inner nerd excited, then check out iSticky - a sticky note app on steroids. Also on the feature list are themes, categories, encryption, document linking and more.
While we don't think iSticky is Universal yet (at least, the author isn't bragging about it on the site), a demo is available. iSticky also offers a wide range of licenses depending on which features you need and whether you need a family/business pack. Prices run from $16 USD (single license, Bonjour sending but not over the web) up to $90 USD for a 12 license pack with all the toppings. Check it out if Apple's Stickies just aren't cutting it for you anymore.