I ran across two products recently that sort of work along the same lines. I haven't had the opportunity to try either one yet.
The Health Tea Wand is made by Wisdom Wands, Inc. and is allegedly "the most remarkable tea accessory ever invented." That's laying it on a bit thick, but like I say I haven't had a chance to try it yet. Maybe it really is.
Anyway, if you're familiar with the bombilla, an ornamental straw with filter that's used to drink loose yerba mate, then you've got an idea what the Health Tea Wand is all about. It's a clear glass straw with fine holes at one end. Brew your loose tea in a glass, stick the straw - err, wand - in and drink. The only issue that's not clear to me is how you keep from oversteeping your tea or keeping the leaves from blocking the filter portion.
The other product is the Ticolino Tea Infuser, from Serengeti Tea Company. This one looks a little bit like a straw, but is actually a single serving packet of tea that you unwrap, pop in your glass, steep and remove. Looks like an okay product too. The only potential issue with this one is that it doesn't seem like the leaves have much room to breathe and get the maximum contact with the water.
Anyway, the TTI is available in three tea and three herbal varieties, though with a minimum order of $40 I'm thinking that it's geared more toward the retail and food service trade.