I told myself that I should learn Esperanto only if I'd ever use it, as I might never find another speaker outside the Internet. Thus, I want to come up with ways to let people around me know they can talk to me in Esperanto...

Making myself a shirt is one idea. What would you put on a shirt?

I considered making a green shirt with a white box in the centre containing a green star.... is that too obscure?

How about: "Ĉu vi parolas ĝin?" in white letters on an otherwise plain black shirt. Maybe a green star on a white square on the back.

It's short and mysterious-looking enough that people who don't "speak it" might be inclined to ask what the phrase means. And I think most Esperanto speakers should be able to figure out what you are referring to.

how about a shirt w/ the esperanto flag and "Ĉu vi parolas ĝin?". I would buy one if available

 

 

Mi pensi, pro tio sumo

I have two types of Esperanto-related T-shirts right now.  They're both white.  One has the following quote, the words of which form the shape of a green, five-pointed star on the upper right side, when looking at it, on the front of the T-shirt:

La tago alproksimiĝas kiam ĉiuj popoloj de la mondo akceptos universalan lingvon kaj komunan skribon.  Kiam tio estas atingita, ĉiu homo, kiu ajn li vizitos, kvazaŭ eniros en sian propran domon...  tiu vere estas homo, kiu hodiaŭ dediĉas sin al la servo al la tuta homaro...  Ne gloru sin tiu, kiu amas sian propran landon, sed tiu, kiu amas la tutan homaron.  La tero estas nur unu lando, kaj ĉiuj homoj ĝiaj civitanoj.

 Bahá’u'lláh

From a distance, the quote looks like a green five-pointed star, yet the words are still sufficently big enough that, if one wanted to read them, he could if he should come within a reasonable distance.

 

The second T-shirt has the words, in Chinese, in black across the front of the T-shirt, which say:

懂得世界语

就懂得世界

冰心

which mans:

To know Esperanto is to know the world.

Bing Xin

 

Bing Xin is famous in Chinese history and is a well respected author of the last centoury, during the time of the Republic of China.  Many Chinese are not aware that she supported, never mind knew, Esperanto, and so that naturally comes as a shock to many who read that T-shirt.

 

Another one I've considered creating would be to have the following words, on a white T-shirt, in red, forming the shape of a cross like that on the English flag:

I have often noted how men are brought into unfriendly relations merely through material hindrance to mutual comprehension. The learning and spreading of Esperanto is therefore undoubtedly a Christian movement, helping to create the Kingdom of God, which is the chief and only aim of human life. -- Leo Tolstoy

Sinse Tolstoy's Christian Faith is what brought him to Esperanto, a cross would therefore be in order, and sinse the words would be in English, what better symbol of the English language than the English flag?  I'm not sure if I'd put it on the front of the back of the T-shirt, though.  I certainly wouldn't put it over my heart, however, sinse it could potentially offend some Christians should I put the shape of a cross over my heart when I'm not a Christian myself.

I've also I've also used Bahá’u'lláh's and Bing Xin's quotes above on the back of name cards in either Chinese or Esperanto.

Another idea I've had for Christians would be to print a quote from the Evangel in Esperanto, in green, in the form of a five-pointed star, over the heart.  I suppose the same principle could apply to any religion, philosophy, ideology or other appropriate quote.

These are just some among the many ideas.

I would definately buy a t-shirt if  they were available in black