Egyptian Desert Subtheme
Merchandise
T-Shirts
Amazon Jungle Subtheme
Dinosaurs
Dino Island Subtheme
Orient Expedition Subtheme
Indiana Jones Theme

Adventurers 
Merchandise
T-Shirts 
Caps 
Bags & Wallets
Stickers & Signs
Keychains & Magnets 
Deck of Cards
TreasureQuest 
Books & Magazines
TS04 T-shirt with Egyptian Desert decoration
This T-shirt was one of the specials at Lego Shop-at-Home from August 23rd to 29th 1999. The special price was $7.00, but it was only available in adult size Large. It is probably not available any more. It is made of 100% cotton by Fruit of Loom. 
TS10 T-shirt with Amazon Jungle decoration
This T-shirt was one of the specials at Lego Shop-at-Home from October 17th to 23rd 2001 at half price. The special price was $7.00 (adult) and $6.00 (youth). It is probably not available any more. It is made of 100% cotton by ONEITA Color Wear. 
For kids there was two sizes: Medium (10-12) and Large (14-16) that costs $12.00. 
For adults there was four sizes: Small, Medium, Large and X-Large that costs $14.00.
T-shirts with Dino Island/Studios decoration
There were three with pictures from the Dino Island subtheme. Besides there was one from the Studios line. The picture showed Johnny Thunder in front of a T-Rex at a film set. That one had sound in it. Press on Johnny Thunder a the shirt said "Come on Rex". Press the director and it said "It's wrap".

One of the T-Shirts showed Johnny Thunder on a beach with a surfboard. The legend was "Let's hit the waves". He wore a red and white horizontally striped T-Shirt (you know the one from the Pirates theme). On that T-Shirt (the striped, not the actual) was written "Sam Grant". I guess that is his undercover name for having fun.

Unfortunately all of the T-Shirts were only available in kids sizes.